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As a contribution to morphological botany tion of the vegetable world that is assumed. nothing approaching the present book from the Despite the similarities in the fructifications paleontological side has ever been produced in these two lines, the reviewer would regard and I am not surprised that Scotti is enthus- the former as a specialized sideline without iastic about it. I would expect Professor issue and probably never more abundant or Coulter to be equally enthusiastic. As a text- important than are cycads in the existing flora, book of fossil plants intended for geological while the latter constituted a more dominant students as its subtitle indicates, or as an ex- and progressive line, more intimately conposition of the geological history of fossil nected with the Paleozoic pteridosperms and plants it is very inadequate, and I regard this having points of contact with possibly the as a serious defect since the great majority of Ginkgoales or the Coniferophytes. The bulk students who will use the book, while they of the frond genera were probably borne by will gain a much wider morphological outlook, plants of the Williamsonia rather than of the will scarcely learn that fossil plants have at- Cycadeoidea type. It may be noted that the tributes other than anatomical, or if they do American Cycadellas come from the Lower they will conclude that such attributes are Cretaceous and not the Jurassic. The author worthless anyway. Nor will they gather the is hardly justified in doubting the bisexual impression that fossil plants are found much character of the so-called flowers of Cycaanywhere except in the Carboniferous, Jurassic deoidea Gibsoniana, nor is it easy to follow him and Wealden.
in his explanation of the corona of WilliamThe proofreading of volume 3 is not as good sonia gigas as morphologically a whorl of conas in the preceding volumes and some of the nate stamens in a central terminal position. illustrations are very poor; nor is the bibliog- When it is remembered that throughout all raphy as complete as it might well have been of the Cycadeoidea species already investimade. A paper by White is credited to gated the megasporophylls become more or less Knowlton, Vignier should be Viguier. Kram- sterile distad and that in some species, as mera (page 277 and elsewhere) should be Wieland has demonstrated, these, together Krannera. The statement on page 276 that with the prolonged interseminal scales, are there is no proof of Cordaites in the Arctic modified to form a mop-like tuft at the apex may be a statement of opinion—it is hardly of the receptacle, and also having in mind the a fact. The statement on page 276 that “it is ears or wings of the microsporophylls that by no means certain that Cordaites flourished formed a canopy over the apex of the recepbefore the Carboniferous” is also misleading. tacle in Cycadeoidea colossalis, it is quite posApparently Seward wishes to restrict the Cor- sible to explain Seward's figures 546 and 547 daitales in their earlier manifestations and ex- in a variety of ways without recourse to the tend them in their later manifestations as in improbable hypothesis that we have terminal the case of Noeggerathiopsis and similar re- microsporophylls. In fact, there is no evimains. Surely Callixylon Oweni described by dence that the so-called microsporophylls of Elkins & Wieland from the Devonian of In- Williamsonia gigas described on page 435 bediana? is ample evidence for the presence of long to that species. Fig. 549 no doubt repreCordaites in pre-Carboniferous rocks. It may sents a synangia-bearing disk of a Williambe seriously doubted if the two types repre- sonia, but there is not the slightest evidence sented by Cycadeoidea and Williamsonia were that it belonged to Williamsonia gigas or that not much more divergent than is indicated, or it should be placed on the end of a Williamif the former were the Mesozoic lords of crea
sonia carpellary receptacle. Similarly the 1 Scott, D. H., New Phytologist, Vol. 16, Nos. 8,
sterile disks or infundibuliform organs have 9, 1917.
not been demonstrated to have been borne on 2 Elkins, M. G., and Wieland, G. R., Am. Jour. the apex of the receptacle. Sci. (IV.), Vol. 38, pp. 65–78, 1914.
On page 89 some poorly preserved Myeloxylon
petioles are appealed to as evidence of the for one reason or another but this does not existence of Medullosa in North America. Of afford any justification for attempting to recourse fronds are not evidence so it may be place them. There is surely a difference bereassuring to state that characteristic sections tween retaining a degree of personal indeof petrified stem material of Medullosa are pendence in the face of codes and the persistcontained in the collections of the U. S. Na- ent refusal to recognize the fact that practises tional Museum, so that it may now be con- of this sort serve only to confuse the subject. sidered proven that Medullosa foliage was, in Cordaianthus Pitcairnæ figured on page 266 life, borne on Medullosa stems in America as is merely a type of inflorescence and is scarcely well as in Europe. It may be questioned entitled to a specific name.
At B in the same (page 87) whether leaf form is more protean figure (Fig. 480) there is figured from the than either vascular anatomy or floral mor- Kidston collection, a specimen which is called phology. Apropos of Seward's remarks on the Cordaianthus Volkmanni. The latter belongs genus Schützia it may be noted that in a paper to the type of inflorescence which Grand'Eury which has apparently been overlooked, Schus- called the gemmifer group, to which this speter3 describes specimens of Schützia anomala cimen does not belong, although it does belong in the Dresden Museum, labelled in Geinitz's to Grand'Eury's baccifer group, and should handwriting, which show definitely that these probably be identified as Cordaianthus subobjects were spore receptacles as had been sur- volkmanni. The genus Holcospermum (page mised.
361) is hardly an improvement on Carpolithus, The forms known as Microzania gibba (page and it would seem that if form genera for 504) and Zamites bohemicus (page 534) come seeds are worth anything at all then Holcofrom the Upper and not the Lower Cretace- spermum should be referred to Zalessky's
It would be far better if the term genus Polygonocarpus. This last genus is Wealden were used to denote a peculiar envir- mentioned under Polypterospermum on page onmental facies as shown in the lithology and 323 where we are told that Radiospermum or not a chronological unit. There is no more Polypterospermum ornatum should probably be reason for calling deposits in all parts of the referred to it, while on page 358 we are told world Wealden than there would be for calling that this species affords another example of the English Wealden deposits Potomac. Polypterocarpus as this generic name is em
On page 278 the genus Pelourdea is proposed ployed by the author. Nowhere is the genus or the long-known Yuccites vogesiacus of Polygonocarpus discussed (it is not even in Schimper & Mougeot because the author con- the index) although it is of some importance, siders it undesirable to retain a designation and, if one may judge from Scott's figures of suggesting false ideas with regard to affinity. Trigonocarpus Parkinsoni, is the proper name No one now supposes that this is suggested for his specimens of the latter. If the reader and such a proposal is entirely unwarranted will turn to Seward's Fig. 426 C he will see and can only be confusing instead of clarify- that the sclerotesta of Scott's Trigonocarpus ing. Moreover it is flying in the face of all Parkinsoni is of exactly the type of Polycanons of nomenclature. A name of a genus gonocarpus. Now if this figure be compared is simply a name, and we use generic names with Fig. 425 on the opposite page, also called for convenience chiefly, and not in a descrip- Trigonocarpus Parkinsoni, it must be appartive or phylogenetic sense. I imagine that ent that the two do not represent the same fully 25 per cent. of the names in systematic seed or the many angles of the former would botany and zoology are equally inappropriate show through the partially preserved sarcotesta 8 Schuster, J., “Uber die Fruktifikation von
of the latter, which is not the case, nor is it Schuetzia anomala,” Sitz. k. Akad. Wiss. Wien,
desirable on general principles to refer strucBand 120, Heft 8, Ab. 1, pp. 1125–1134, Pls. 1, 2,
tural material to form genera based upon 1911.
As an instance typical of that unevenness selected for figuring in the present work withof treatment previously mentioned the genus out any digestion of the subject simply because Samaropsis may be examined with some slight the names occur frequently in the literature, detail. In Fig. 502 A on page 350 are shown a method of procedure which not only entirely three figures copied from Dawson of Sama obscures any chronologic value that these obropsis fluitans. This species is apparently jects might have, but crowds out figures or disselected for discussion and illustration since cussion of really good material. The case may this name appears in many lists of Carbonif be stated something as follows: The poorer erous fossils from various localities. Dawson's the type material of a species the more readily figures are notoriously unreliable, as is very well will other things be confused with it and so known on this side of the Atlantic, and his in the course of time it is always the least types of Samaropsis fluitans scarcely deserve recognizable and the poorest types that become to be taken up as the types of anything. Now credited with the greatest range, both geologif we turn to Samaropsis fluitans as identified ical and geographical. by Weiss we find that it represents an alto This sort of criticism might be legitimately gether different object. Similarly Kidston's applied to many other items in the present and Zeiller's Samaropsis fluitans, while they volume. These are almost always subjects are identical with one another, can hardly be outside of Professor Seward's own specialty, considered as identical with either Dawson's and subjects in which I fancy he is not greatly or Weiss's objects so named and Grand'Eury's interested, and while they do not detract from Samaropsis fluitans is a still different object. the value or accuracy of that part of the work Turning to the second species shown in this where the author is on familiar ground, an figure, namely Samaropsis emarginatum of author should not pose as an authority on Goeppert & Berger, we find that the type phases of work in which he shows no apparent figures are absolutely unrecognizable. We find interest or willingness to give the labor necesthat Geinitz referred two totally different sary to the mastery of the literature, so much forms to this species, Hoffman & Ryba's deter of which it is admitted is of minor value. mination of it is questionable, Feistmantel's For this very reason and the further reason forms of this name are still different, and previously mentioned of Seward's attitude reKidston's figures of 1902, 1908 and the pres garding what constitutes a fossil species, it ent work can scarcely regarded in any single may be considered very fortunate that the instance as representing any of the previous author has been unable as yet to carry out determinations. If we turn now to C and D his intention of discussing the geographical of this same figure, supposed to represent Cor and geological distribution of fossil plants. daicarpus Cordai of Geinitz we find that
EDWARD W. BERRY Geinitz figured a variety of things under this THE JOHNS HOPKINS UNIVERSITY, name, but he expressly states in his text that
BALTIMORE, MD. these seeds are 2 cm. in diameter and sometimes twice that size and tumid. When we
SPECIAL ARTICLES turn to Zeiller's, Kidston's or Vernon's figures THE GLASS SANDS OF PENNSYLVANIA called by this name we find a tiny, often flat,
At present in the manufacture of glass, form, totally unlike anything that Geinitz
nearly pure quartz sands are used almost exfigured. It may also be suggested that E of
clusively as the source of the silica which is this figure is upside down and that instead of the major constituent of all the common vahaving a Samaropsis bicaudata we have a rieties of this useful substance. An ideal Samaropsis bicornuta, for which there are glass sand would be one made up entirely of analogies in other species of Samaropsis. grains of the mineral quartz. Sands contain
These instances may be taken to illustrate ing 100 per cent. silica, however, are not found my criticism that unsatisfactory forms were in nature, although some very nearly approach
this composition. When a complete chemical one usually developed. Where the amount of analysis of a glass sand is made, minute iron present is small, this coloring effect can amounts of alumina, ferric and ferrous oxides, be in part overcome by the use of manganese magnesia, lime, titanium oxide, traces of the dioxide, nickel oxide or selenium. For the alkalies, and varying amounts of water are best grades of optical glass the percentage of usually found to be present. Some of these ferric oxide present in the sand should not constituents are harmless, while others have a exceed .002 per cent. For the better grades very deleterious effect upon the glass.
of lead flint used in the manufacture of cut Alumina imparts both desirable and unde- glassware it should not exceed .02 per cent. sirable properties to the resulting glass. It In the case of plate glass to be used for mirrors reduces the tendency of the glass to devitrify the ferric oxide should not be over .1 per cent., or crystallize. It decreases the solubility of while in the case of plate glass to be used by the glass in water, weak acids, and other re- transmitted light it may run up to .2 per agents, which is very desirable in the case of cent. For window glass the amount may be bottles and chemical glassware. It increases as high as .5 per cent., while in the case of the surface tension of the glass when chilled ordinary green and brown bottles sands conrapidly, which is beneficial in molding, as the taining from .5 to as high as 7.0 per cent. glass will not take on the minor imperfections
ferric oxide is used. Iron may be present in of the mold, while, on the other hand, it will the sand in the form of limonite, hematite, still be sufficiently viscous to assume the gen- magnetite, ilmenite, biotite, hornblende, or eral shape of the mold. It reduces the co- chlorite. A little may also be introduced as efficient of expansion of the glass and increases metallic iron from the machinery used in its tenacity, a feature also desirable in the case crushing the sandstone to sand.
If it is presof bottles and chemical glassware. Alumina ent as limonite or hematite closely associated in glass facilitates annealing. It also makes with the kaolinite or clay, it may be in large the glass somewhat harder and a little more part removed by washing. If, on the other brilliant. An undesirable feature is that alu- hand, the limonite or hematite adheres closely mina tends to decrease the fusibility of the to the quartz grains washing will be of no glass and increases its viscosity. It should, avail. The other minerals mentioned can not therefore, not be present in amounts exceeding be readily removed by washing. 3 per cent. Also glass cullet containing alu- The small amounts of magnesia and lime mina does not mix well with other glass and, occasionally present in glass sands have no therefore, tends to produce cords or striæ when detrimental effect upon the glass. All the used. The light blue tint noticeable in cer- common varieties such as plate, window, and tain glasses made from salt cake is thought bottle glass contain lime as an essential conby some observers to be due to alumina in the stituent. Magnesia is much more apt to be form of a compound analogous to ultramarine introduced into the glass batch through the blue. Alumina may occur in glass sands in limestone used than through the sand. The the form of kaolinite, mica, feldspar, or horn- composition of this material, therefore, must blende. If it is present as kaolinite or mica be watched with respect to this constituent. it may be largely removed by washing.
Alkalies, likewise, enter into the composition Iron in the form of either ferric or ferrous of glass and the minute traces occasionally oxides is the most detrimental impurity found present in the sand, therefore, are not harmful. in glass sands on account of its coloring effect Titanium oxide never occurs in sufficient upon the glass. Ferrous iron imparts a bluish amounts to have any detrimental effects upon green tint upon glass, while ferric iron pro- the glass. It usually occurs in the sand as duces a yellow tint, which is not nearly so minute hairlike inclusions of rutile in the noticeable. Since most glass is made under quartz grains, themselves. In the case of the reducing conditions, the green color is the better grades of glass such as optical, lead
flint, and plate, the sand is always carefully glass sand. For this purpose the sandstone dried before being used.
must be sufficiently friable so that small pieces In size for ordinary purposes of glass manu may be broken up between the fingers into facture practically all of the sand grains loose sand. In preparing it for the market should pass through a 30-mesh sieve, or in the rock is passed through a jaw crusher and other words have a diameter less than .64 chaser mill or wet grinding pan to disintegrate millimeters. The majority of the grains should it into loose sand. It is then screened, passed be retained on a 120-mesh screen, or be over through a screw conveyor type of washer, the .136 millimeters in diameter. For optical excess water is allowed to drain off, and the glass, all of the sand should pass through a sand is dried in a steam or direct heat dryer. 48-mesh sieve. The shape of the grains has After a final screening it is ready for the little to do with the relative values of the market. Much of the best grade of glass sand sand, although perhaps an angular sand is a produced in the United States comes from this little more desirable than one in which all of district. the grains are well rounded, other factors be The Pottsville formation of western Penning equal.
sylvania is divided into five members as folIn 1915, Pennsylvania produced 455,112 tons lows, commencing at the top: the Homewood of glass sand. This represents about one sandstone, the Mercer shale, the Connoquenesfourth of the total production of glass sand in sing sandstone, the Sharon shale, and the the United States. Pennsylvania holds this Sharon or Olean conglomerate. Of these porimportant rank as a producer of glass sand for
tions of the Homewood and the Connoquenestwo reasons: first there are found within her sing sandstones are at times sufficiently pure borders an abundant supply of nearly pure quartz sandstones to be available for glass quartz sandstones that yield when crushed an sand. The sand derived from them, however, excellent grade of sand, and secondly the center is never as pure as that from the Oriskany of of the glass industry of the United States is central Pennsylvania and is, therefore, used located in western Pennsylvania so that there only in the manufacture of the cheaper grades is a great demand for such sand. Nearly all of glass such as bottle and window glass. A of the glass sand at present produced in little is also used in the plate-glass industry. Pennsylvania comes from two formations, the
The method of treatment is usually the same Oriskany of the Devonian and the Pottsville as that used on the Oriskany sandstone in of the lower Pennsylvanian. Of these the central Pennsylvania, except that drying is Oriskany is by far the more important.
usually dispensed with. Sometimes, however, The Oriskany formation occupies the belt the rock is simply crushed dry and screened, of Appalachian folding which crosses Central washing not being resorted to. Pennsylvania and which reaches a maximum
CHAS. R. FETTKE width of nearly 56 miles. It varies greatly in this area both in thickness and in character.
SCIENCE In Huntingdon and Mifflin counties a pure quartz sandstone phase, which has a thickness A eekly Journal devoted to the Advancement of of from 60 to 200 feet, is particularly well Science, publishing the official notices and prodeveloped. In its unaltered state it is a hard ceedings of the American Association for bluish-gray quartzite made up of interlocking
the Advancement of Science grains of quartz in which silica in parallel
Published every Friday by orientation with the original grains is the
THE SCIENCE PRESS bond. Under favorable conditions of weathering this has become disintegrated to a friable
GARRISON, N. Y. sandstone, or in some places even to a loose
NEW YORK, N. Y. sand. These are the portions that are used for Entered in the post-office at Lancaster, Pa., a second clan matter