ity can be selected.

It has been said by Nægeli that "the consequences of fertilization reach their optimum when a certain mean difference in the origin of the sexual cells is attained"; and by Fritz Müller, that "every plant requires, for the production of the strongest possible and most prolific progeny, a certain amount of difference between the male and female elements which unite. Fertility is diminished as well when this degree is too low (in relatives too closely related) as when it is too high (in those too little related)." Darwin says: "The offspring from the union of distinct individuals, especially if their progenitors have been subjected to very dif

using crossed seed. The practical va fact is indicated by results obtained nois Experiment Station by Morrow ner in crossing various races of corn. bred corns tested, 12 gave a decided yield over that of the parent sorts, ra 2 to 86 per cent in individual cases. In a decrease in yield of from 8 to 2 resulted. In the 15 cases taken t average increase in yield of about 1 was secured. In some cases the cross were grown to the second generati crossing and showed a decidedly la than the parent varieties. A number experiments of a similar nature had

808

j

9

FIG. 3.

a

ferent conditions, have an immense advantage in height, weight, constitutional vigor, and fertility over the self-fertilized offspring from one of the same parents."

Attention has been called by Willis to three factors in the gain resulting from cross-fertilization, namely, a, fertility of mother plant; b, vigor of offspring; and c, fertility of offspring. The relative value of these factors varies with different plants. In the carnation, for instance, factor a of cross-fertilized plants was 9 per cent greater than in self-fertilized plants, b was 16 per cent greater, and c was 54 per cent greater; in tobacco, factor a was 33 per cent less than in selffertilized plants, but factor b was 28 per cent greater, and factor c 3 per cent greater. Even when the fertility of the mother-plant is greatly reduced by hybridizing with a distinct species and the hybrids themselves are sterile or very infertile they nevertheless often show extraordinary vigor, that is, b is often greater in hybrids

been made by McCluer with corn and the same results obtained. McCluer "The corn grown from the crossed nearly all cases clearly increased in result of crossing," and that "nearly grown a second year from the crosse than that grown the first year, thoug is yet larger than the average size of varieties.»

In maize, the loss of vigor caus in-breeding was found in experiment by the writer, in conjunction with Hartley, to be very marked. Seeds King, a race grown commonly in States, produced by in-breeding wit the same stalk, yielded the next year per 100 stalks of 46 ears, weighing Seeds of the same race, in every wa ble, but produced by crossing differer yielded under the same conditions at 100 stalks of 82 ears, weighing 271⁄2

attempting to fix hybrids of Hickory King crossed with Cuzco or Peruvian corn, some ears were inbred with pollen from the stalks bearing them, while others were pollinated from other hybrid seedlings of the same parentage. The hybrids of the second generation, where the seed was inbred with pollen from the same stalk, showed great loss of vigor, being small in stature and almost totally sterile; while those produced from seed which was inbred with pollen from a different seedling were much more vigorous and productive, seeming to have lost but little by this process of inbreeding. In the majority of cases crossing distinct sorts improves the vigor and results in greatly increased yield. By selecting varieties which have increased yields uniformly when crossed and crossing these for seed corn, it seems certain that the average yield can be greatly increased. Securing seed corn from a cross of any two races desired is not a difficult or expensive process, being easily accomplished by planting the two desired sorts in alternate rows and removing the tassels, as soon as they appear, from the one to be used as the female parent. The ears that form on the rows from which the tassels have been removed will have been crossed with pollen from the variety from which the tassels have not been removed. The seed corn should therefore be selected from the ears produced on the detasseled rows. The field planted to the two varieties, as above described, to secure crossed seed should be somewhat isolated from other cornfields, and should be of sufficient size to produce the necessary quantity of seed. The only extra expense incurred in producing seed corn in this way is the cost of detasseling the alternate rows, as ears will form on both as usual.

The increased vigor and fruitfulness which almost invariably result from crossing closely related sorts or varieties is a principle of the utmost importance in our common agricultural practices, for there is a great need for more vigorous forage plants, timber and shade trees, vegetables, etc., and more prolific grains and fruits.

Self-sterile Plants.-Some plants have become so completely modified for cross-fertilization that they are sterile to their own poller and will not set seed unless cross-fertilized. Of our wild plants this has been found to be the case in a number of instances. Koelreuter and Gärtner long ago found that some plants, namely, Verbascum phoeniceum, V. nigrum, and Lobelia fulgens, under certain conditions were sterile to their own pollen, but would set seed abundantly when crossed with pollen of other species. Fritz Müller proved by careful experiment that Eschscholtzia californica, Abutilon Darwinii, and a species of begonia were sterile to their own pollen, whether fertilized with pollen from the same flower or from different flowers on the same plant, but were perfectly fertile when cross-pollinated with pollen from other plants. Darwin found that these plants in England were also largely self-sterile, but that under certain conditions the degree of fertility with their own pollen could be greatly increased. The same phenomenon of self-sterility and necessity for cross-pollination is shown by some of our important cultivated plants. Mr. M. B. Waite has demonstrated that many of the varieties of pears, such as Bartlett, An

jou, etc., are largely self-sterile, producing few or no fruits when pollinated only with pollen of the same variety. In the case of varieties of pears and fruits of this kind that are propagated altogether by budding, as is well known, all of the various trees of the variety that exist are simply parts of the same individual, so that pollinating flowers on one Bartlett pear-tree with pollen from another Bartlett pear-tree is in effect the same as pollinating one flower on a plant with pollen from a different flower on the same plant and is what we recognize as self-fertilization. Mr. Waite and others have shown that when such sterile varieties are pollinated from a different horticultural variety, which in reality is simply a different individual of the same species, they are rendered perfectly fertile. This discovery has proved of great practical value, as many pear orchards were planted with trees of a single variety like the Bartlett and were found for some unknown cause to be very unfruitful. Waite's discovery showed the true cause of this lack of fruitfulness and at the same time pointed out the natural and simple remedy of cross-fertilization. All that remained to be done in such barren orchards was to bud some of the trees over with buds of varieties which had by experiment been found to produce a good percentage of fertility in crossing on the variety concerned. Since Waite's discovery of the reason for the barrenness of certain varieties of pears many experiments have been conducted by different investigators. It is now known as a result of experiments by Waite, Waugh, Beach, and others that many varieties of plum and apple are largely sterile to their own pollen and require cross-pollination for complete fruitfulness.

The pineapple, also, as shown by the writer's studies is an interesting example of a self-sterile plant. Ordinarily the pineapple is wholly seedless, yet the flowers are so arranged that they are abundantly fertilized with their own pollen. The self-sterility is so perfect that even under these circumstances, seeds set so rarely that few growers and consumers have ever seen seeds. In experiments in crossing various varieties it was found that when certain varieties were crossed seeds were formed in abundance, showing that cross-fertilization is necessary to insure the development of perfect seeds. The explanation for the setting of such few seeds in cultivation normally is probably to be found in the fact that the proper insect pollinators are not present, and the flowers are therefore not cross

fertilized.

CROSS-FERTILIZATION IN ANIMALS AND IN MAN. In animals and man, as stated above, crossfertilization means the crossing of individuals of different races or breeds in contradistinction to in-and-inbreeding in which different closely related individuals of the same race or breed are bred together. With animals as with plants, benefit results from occasional_cross-fertilization, at least within certain limits. The evil effect from the closest possible inbreeding with animals, however, is not nearly so marked as in plants and in some cases its deleterious effect is hardly apparent. Inbreeding, interbreeding, or close breeding, which means the breeding together of closely related animals at rather distant or long intervals, and not every generation, seldom or never results in evil effect. It is the continuous

in-and-inbreeding of closely related individuals, generation after generation, without intermission, that is claimed by some to lead to evil effects. The opponents of in-and-inbreeding claim that it results in delicacy of constitution, predisposition to disease, lack of fecundity, etc. It must be admitted that those breeders who have used in-and-inbreeding the most, use the method as a means to an end and not because they believe primarily in any beneficial result of in-and-inbreeding in itself. As a result of long experience in the fixation of desirable characters it has been found that this is the surest and best way to render a character prepotent. It is used, therefore, as a means of strengthening the transmitting power or prepotency of a character, which otherwise in most instances would be lost. Miles states that "From a careful examination of the pedigrees that may be found in the herd books and breeding-registers, representing the practice of breeders of acknowledged reputation, it will be found that in-andinbreeding has only been resorted to in the case of some favorite animal or animals that were superior in certain respects to the average members of the herd or family which they represent, and the object has evidently been to secure in the offspring a predominance of their most highly valued characters." In most instances the older original character is more strongly hereditary and it is only by in-andinbreeding that a new character can be rendered stable and prepotent and prevented from being swamped and lost. Such new characters in some cases have by this means been so strengthened that they dominate even the original and older characters. In regard to the belief that in-and-inbreeding leads to sterility and predisposition to disease, a careful consideration of the evidence at command leaves the student in doubt as to the conclusion to be drawn. Although in some instances there is a tendency to sterility, in other cases full fertility is maintained and the same conflicting statements may be made regarding weakness and tendency to disease. The facts seem to indicate that close breeding or in-and-inbreeding in itself is not injurious, but may be very detrimental in some cases, as it tends to perpetuate any constitutional defects which may have been produced by other agencies. In-and-inbreeding should always be accompanied by the closest selection of the best animals free from constitutional weakness or disease. The greatest objection to in-and-inbreeding lies first in the difficulty experienced in selecting breeding animals that are free from any constitutional weakness, as such defects frequently do not become distinguishable till after the breeding has progressed several years; and second in the danger that such defects may become dominant in the offspring. It must be admitted, however, that when used judiciously in-and-inbreeding forms an important means of securing improvements and is the only known means of fixing and rendering slight variations hereditary.

The majority of our various breeds of cattle have been brought up and improved as a result of very close inbreeding. As an illustration, the famous shorthorn bull, Favorite, was bred to his daughter, granddaughter, and great-granddaughter, and the product of the last union was matched with the bull Wellington, having 62.5 per cent of the blood of Favorite. Clarissa, the

offspring of the last union was bred with the bull Lancaster, having 68.75 per cent of the blood of Favorite and gave very valuable offspring. The majority of our best breeds of animals have been very closely in-and-inbred without very noticeable deterioration in any direction except possibility in fecundity. It must be borne in mind, however, that this in-andinbreeding has at every step been accompanied by the most rigorous selection, only the very best animals being retained for further breeding. Darwin says that "Although by careful selection of the best animals, close interbreeding may be long carried on with cattle, yet the good effects of a cross between almost any two breeds is at once shown by the greater size and vigor of the offspring; as Mr. Spooner writes to me Crossing distinct breeds certainly improves cattle for the butcher. » The benefits of crossing are particularly visible when following extended in-and-inbreeding.

In the case of man, where families have interbred very closely, as has sometimes occurred, there is said to be a great gain in vigor as a result of intermarriage with a distinctly different family. The hardihood and general vigor of the Americans as a nation is commonly attributed to the great intermixture of peoples of many different nationalities. The mixture of European races has been going on from prehistoric times, and the population is of highly composite character. The results of mixtures of the various strains, breeds, or stocks of the white race are without doubt very beneficial, resulting in increased strength and vigor, and the same can be said of the intermixtures of the various strains or stocks of the yellow, brown, or black races. Here as in plants Nature abhors too close interbreeding. On the other hand, inter-racial marriage, or miscegenation, the marriage of individuals of distinct races, as a whole, results very disastrously both as to physical and mental characteristics. The result of such a union is a hybrid, frequently sterile, mainly intermediate in characters between the two races, and usually in large measure a social outcast. Such half-breeds or hybrids are in general inferior to the pure parental races, particularly in physical vigor, though mentally they may be equal or possibly superior. In crosses, for instance, of the negro and white races, the offspring commonly shows a tendency toward sterility and are in general weak in constitution.

In conclusion it may be stated that injury results on the one hand from too close inbreeding and on the other hand from crossing races too distinct, but that the crossing of slightly distinct strains and of individuals, reared under different conditions, is beneficial. See FERTILIZATION.

Bibliography.- Grant Allen, On the Colors of Flowers (1880); Bailey, Plant Breeding (1895); Darwin, Various Contrivances by which Orchids are Fertilized by Insects' (1877), 'Effect of Cross and Self-fertilization in the Vegetable Kingdom (1878); 'Different Forms of Flowers on Plants of the Same Species' (London 1880), and The Variation of Animals and Plants under Domestication' (1892); Henslow, 'Origin of Floral Structures' (1893); Lubbock, British Wild Flowers Considered in Relation to Insects' (1882); Miles, Stock Breeding (1888); Müller, The Fertilization of Flowers (1883); Swingle and Webber, 'Hybrids and Their Utili

zation in Plant Breeding' (Year-book U. S. Department of Agriculture, 1897); Waite, 'The Pollination of Pear Flowers' (Bull. 5, Div. Veg. Pathology, U. S. Department of Agriculture, 1895); and Wallace, Darwinism' (1889).

HERBERT J. WEBBER,

U. S. Department of Agriculture. Cross-fire, the combination of intersecting lines of fire from two or more parts of a work. It is frequently made use of to prevent an enemy's passing through a defile. The flanks as well as the faces of two adjoining bastions afford the means of cross-fire, as do also the faces of two adjoining redoubts.

Cross-fox, a peculiarly marked northern variety of the American red fox. It has a dark line along the back, and crossing this a stripe on the withers. This gives its name. Its rarity and beauty make its skin more valuable than is the pelt of the ordinary fox.

Cross Keys, Va., a place in Rockingham County, 20 miles northeast of Staunton, where a battle took place 8 June 1862, between the Union and Confederate forces. The former numbered about 18,000 under Gen. Fremont and lost 625 men; the latter had about 8,000 men under Gen. Ewell and lost 287.

in

Cross Keys, Battle of. On the morning of 8 June 1862 Gen. Frémont, with 10,500 men and 44 guns marched from Harrisonburg, Virginia, following Gen. "Stonewall Jackson, who had been pursued up the Shenandoah valley, and who had now fallen back the direction of Port Republic. Frémont's cavalry drove in Jackson's, and when eight miles beyond Harrisonburg Cluseret's brigade, in advance, came upon Gen. Ewell's division of about 5,000 men and 16 guns, at Cross Keys, and Frémont formed for attack. Cluseret's brigade, with artillery, was on and near the road, Stahel's and Bohlen's were sent on the left; Milroy's and Schenck's on the right. Eight batteries were put on the line and opened a spirited fire. Stahel was now ordered to attack Ewell's right and, going forward, met with some success, but when his two left regiments were ascending a gentle slope and had approached within a few feet of its summit, Ewell's men opened with an unexpected and severe fire, and the regiments were repulsed with great loss. Part of Ewell's line pursued, but was checked and driven back by Stahel's right regiment, which was concealed in the woods. Bohlen's brigade was now ordered forward, but under, conflicting orders it was misdirected, and for the most part remained as support to the batteries. Re-enforcing his own right, Ewell advanced beyond Frémont's left, got an enfilading fire on his batteries, which, not properly supported, were withdrawn, the infantry following a full mile. Meanwhile on the right Milroy and Schenck had made some progress, and were preparing to make a determined attack on Ewell's left, when Frémont ordered them to fall back and re-enforce his left, but by this time his left had been forced back, and the entire line fell back at 6 P.M. to organize for a renewal of the battle in the morning. During the night and early in the morning Ewell withdrew, under Jackson's order, to join in an attack on Gen. Shields, who was nearing Port Republic by way

of Luray Valley. Frémont followed Ewell to the
south fork of the Shenandoah, to find that he
had burned the bridge behind him and joined
Jackson. He was an idle spectator of the battle
of Port Republic, 9 June, in which his comrades
were defeated, and the day following he returned
to Harrisonburg. The Union loss at Cross Keys
was 558 killed and wounded and 127 missing.
The Confederate loss was 273 killed and wound-
ed, and 15 missing. Consult: 'Official Records,'
Vol. XII.
E. A. CARMAN.

Cross, The Southern. See SOUTHERN CROSS.
Cross, Victoria. See VICTORIA CROSS.
Cross Vine. See BIGNONIA.

Crossbar Shot, a projectile constructed in such a manner as to expand on leaving the gun ball at the end of each arm,- formerly used at into the form of a cross with one quarter of the sea for injuring the enemy's rigging, and doing general execution.

Crossbill, a bird of the genus Loxia belonging to the finch family (Fringillide) and unique from the character of the bill the two mandibles of which are twisted awry so that they cross. This peculiarity has given rise to a well-known and pretty legend to the effect that the crossed beaks is a mark of the bird's pity in having attempted to draw the nails which held the red plumage of some species is the dye of Jesus' hands and feet to the cross, and that his blood. This singular structure, having the appearance of a deformity, is in reality a wonderfully efficient mechanism for tearing asunder and extracting the seeds of pine cones on which these birds largely feed. Two species belong to the North American fauna, the red crossbill (L. curvirostra) and the white-winged crossbill (L. leucoptera). Both are birds of the northern pine and spruce forests, breeding within the United States, which they do in the very early spring, and only in the extreme northern States and the higher mountains. They are better known as irregular winter wanderers, which appear in flocks usually containing both species, remain in a neighborhood until they have devoured all of the seeds of Closely related species are found in Europe and conifers which are to be found, and then leave. Asia.

Crossbuns, small cakes specially prepared for Good Friday, and in many towns of England cried about the streets on the morning of that day as "hot crossbuns." Good Friday buns were appropriately marked with the cross, and hence the name. At Chelsea there were formerly two celebrated bun-houses, besieged on Good Friday from morning till night by hundreds of eager purchasers, but they have long since disappeared. In many of the cities of the United States, "hot crossbuns" are becoming quite common the last days of Lent.

Crosse, Andrew, English physician and scientist: b. Broomfield, Somerset, 17 June 1784; d. there 6 July 1855. He passed the greater part of his life experimenting in electricity. In 1816 he asserted that by electricity it was possible to communicate one's thoughts instantaneously to persons in the most distant parts of the earth, but he never appears to have attempted to demonstrate the fact by actual experiment. Among other things he applied electricity in the production of crystals, discovered

a process of purifying salt water by electricity, and also made some curious discoveries relative to the effects of positive and negative electricity on vegetation.

Croswell, Edwin, American journalist: b. Catskill, N. Y., 29 May 1797; d. Princeton, N. J., 13 June 1871. His able management of his father's paper, the Catskill Recorder, led Martin Van Buren and other prominent Democrats to invite him to become editor of the Albany Argus, and also State printer 1824. During his 30 years' control he made it one of the most influential Democratic papers in America, and as a member of the political group known as the "Albany Regency," he preserved order in the party ranks through the columns of his paper. His articles were regarded as authoritative and were widely copied. Subsequently he found himself opposed to Van Buren and other early friends, and leaving journalism (1854)

went into business in New York.

Croswell, Harry, American writer and clergyman: b. West Hartford, Conn., 16 June 1778; d. New Haven, Conn., 13 March 1858. He first came into notice as a Federalist editor of The Balance, a newspaper published in Hudson, N. Y. (1802), his bitter and sarcastic editorials involving him in numerous libel suits. Alexander Hamilton's last, and one of his finest, forensic efforts, was made in defense of Croswell in a suit caused by an article on Jefferson. He entered the Episcopal ministry in 1814, became rector of Trinity Church, New Haven, Conn., 1 Jan. 1815, and remained there until his death. He published: (Young Churchman's Guide (1838); 'Family Prayer) (1843); 'Memoir of Rev. W. Croswell (1853); Guide to the Holy Sacraments' (1857).

Crotalaria, krō-ta-la'ri-a, or Rattle-box, a genus of annual and perennial herbs and some shrubby plants of the natural order Leguminosa. The numerous species are widely distributed in the tropical and temperate zones, in the former of which some of the tall growing straight stemmed species yield a textile fibre. The most important of these species are C. juncea, which yields the Sunn hemp of India, and C. tenuifolia, by some botanists considered a variety of the preceding species, which yields Jubblepore hemp. These plants are grown thickly in order to produce attenuated stems with long strands of fibre. If sown thinly they branch freely. Several American species are reputed to cause trouble (crotalism) to horses which eat them too freely. A few species are cultivated for ornament both out of doors and in green houses. The most popular outdoor species is probably C. retusa, a hardy annual herb about one and a half feet tall and bearing racemes of yellow and purple rather fragrant flowers dur

ing summer.

Crotalidæ, krō-tăl'i-dē (Gr. "rattle-like"), a family of venomous serpents of the group Solenoglypha, and considered by Prof. Cope to be most specialized in respect to their poison apparatus of all snakes. In the Solenoglypha the maxillary bone is very short, and so articulated that when the mouth is opened as the snake strikes, the venom fangs are erected; otherwise they are depressed. No other teeth than the functional and prospective poison fangs are borne on the maxillary bone. This family is

distinguished from the Viperide (q.v.) to which it is most closely related by the presence of a deep sensory pit before each eye, on which account the name of pit-vipers is often given to them. With the exception of a couple of Indian and Malayan species closely related to the West Indian fer-de-lance, all of the 60 or 70 species are American. South and Central American species of the genus Lachesis allied to the fer-de-lance the family includes the copperheads, water-moccasins and rattlesnakes of the United States (qq.v). Consult: Cope, Scaled Reptiles of North America,' Rep. U. S. Nat. Mus. (1898).

Besides the numerous

Crotch, William, English musical composer: b. Norwich 5 July 1775; d. Taunton, England, 29 Dec. 1847. As a child he showed astonishing precocity, and at the age of 22 was appointed professor of music at Oxford University, with the degree of doctor of music. In 1822 he became principal of the Royal Academy of Music. He left a large number of compositions, more especially for the organ, piano, and voice, and technical treatises. Among his works may be mentioned: Palestine, an oratorio (1812); 'Elements of Musical Composition' (1812); Specimens of Various Styles of Music' (1813); and 'Captivity of Judah,' an oratorio (1834).

Cro'ton, the popular name of the genus Codicum and the botanical name of another genus of the natural order Euphorbiacea. The former genus consists of about half a dozen shrubs or trees with monoecious flowers in long, slender axillary racemes, and thick leaves resembling those of the aucuba. These few species have given rise to a very large number of varieties of the most diversely colored foliage and of great variety of form. of the Malay peninsula, but are popular throughThey are natives out the civilized world as ornamental plants grown out of doors in warm climates, and in greenhouses in cool countries, where they are planted in beds in parks and gardens during the summer. They must be removed to the greenhouse at the approach of frost. They are easily propogated from cuttings, easily cultivated in ordinarily good soil, and in rather high temperatures, but demand abundant light, and frequent syringing with insecticides to destroy the mealybug. More than a hundred varieties are cultivated in American greenhouses.

cies of widely distributed trees, shrubs, and The genus Croton consists of about 500 speherbs sometimes dioecious but usually monocious, the flowers generally being in terminal which are nearly all annual herbs, have attracted racemes or spikes. The few American species, little attention. Many of the species are very

acrid, some are fragrant, aromatic, or balsamic. C. gratissimus furnishes a cosmetic and perfume which is popular in South Africa; C. flavens, a West Indian species, also yields a perfume. Several species have been used in medicine, among the best-known being C. eleuteria, which yields copalche bark, and C. tiglium, from the seeds of which croton oil is expressed, an oil which was formerly used as a purgative, but has lost its popularity to a very large degree. This last species is a small Asiatic tree with pointed egg-shaped leaves showing various lus