On the Cause of the Variation in the Eggs of British Birds.
By O. GROOM-NAPIER.

On the Crustacea, Echinodermata, Polyzoa, and Colenterata of the Hebrides. By the Rev. A. MERLE NORMAN.

On the Structure and Growth of the Ovarian Ovum in the Gasterosteus Leiurus. By Dr. W. H. RANSOM.

The author described the mode of growth of the early ovarian ovum, and drew attention to the contents of the germinal vesicle, which he showed to be gelatinous; to the germinal spots, which he showed to be drops of a thick fluid, apt to undergo singular changes of form, somewhat resembling those met with in pus corpuscles; and to the yelk sac, which he showed was present at a very early stage of the formation of the egg; and he endeavoured to prove that it increased in all dimensions by interstitial deposition.

On the Systematic Position of the Pronghorn (Antilocapra americana).
By P. L. SCLATER, M.A., Ph. D., F.R.S.

The author stated that his chief object in the present communication was to bring into more prominent notice a very important discovery regarding this animal, that had been made in the Zoological Society's Gardens in the Regent's Park during the past year, and had formed the subject of a paper read by Mr. Bartlett, the Superintendent of the Gardens, at one of the Society's meetings in 1865*. This discovery was, that the horns of the Pronghorn were naturally shed every year-a phenomenon hitherto quite unknown among the Bovidae or hollow-horned Ruminants, with which the Pronghorn had always hitherto been associated, and only occurring in the allied Deer-family or Cervidae. Mr. Bartlett's observations had been made upon a young male of this scarce mammal, which had been acquired for the Society in January 1865†, and had since lived in good health in the Menagerie. This animal had shed both its horns on the 7th of November, 1865; and a finer pair had since grown, which would, no doubt, be shed in like manner in Nov. 1866. Since Mr. Bartlett's publication of this novel fact, full confirmation of it had been received by the Zoological Society, in a communication from their Corresponding Member, Dr. Colbert A. Canfield, of Monterey, California, who had come to the same conclusion as Mr. Bartlett, from observations on this animal in a state of nature made in the county of Monterey, in some parts of which the Pronghorn was very common‡.

The author exhibited a skull of the Pronghorn with the horns fully developed and ready to be cast off shortly, and explained the mode in which he supposed the shedding to be effected. After the old horn was cast off, the horny matter, which was at first entirely confined to the upper end of the new horn, gradually spread itself down to its base, enveloping the numerous hairs with which the new horn was clothed when first appearing, and ultimately checking their growth_and destroying their vitality. After the horn was perfected and hardened, new hairs developed themselves beneath the epidermis, and, not being able to force their way through the horny covering, became, as the author believed, the chief agent in causing the shedding of the horn. As regards the general structure of the horns of the Pronghorn, it was quite evident that they had little or nothing in common with those of the Deer. The latter were formed of bone developed upon a process of the frontal bone, and were more correctly termed antlers, whereas the horn of the Pronghorn consisted of true horn (like those of the ordinary Bovidae) gradually developed from the epidermis, the skin remaining complete underneath them.

Two other points in which the Pronghorn differed from all the other known "Remarks upon the Affinities of the Prongbuck," by A. D. Bartlett, Superintendent

of the Society's Gardens. (Proc. Zool. Soc. 1865, p. 718.)

+ See notice and figure, Proc. Zool. Soc. 1865, p. 60, pl. 3.

See Dr. Canfield's paper "On the Habits of the Prongbuck, and the periodical shedding of its horns," Proc. Zool. Soc. 1866, p. 105.

Bovidae, were the furcation of the horns and the absence of the "false hoofs," as the stunted terminations of the rudimental second and fifth digits of each foot are termed, in which latter respect it resembled the Giraffes (Camelopardalis). These three important modifications of structure, when taken together, induced the author to believe that it would be necessary to raise the genus Antilocapra to the rank of a family in the series of Ruminantia, which he proposed to arrange somewhat as given in the subjoined Table.

3-3; canini

aut

molares

6-6 6-6'

a' Pedes didactyli, ungulis succenturiatis nullis.

a". Cornua in sutura coronali posita, ossea, brevia, pelle
tecta

b". Cornua ex osse frontali orta basi ossea, parte superiore
cornea, furcata, decidua...

b'. Pedes tetradactyli ungulis, succenturiatis duabus.

d''. Cornua ex osse frontali orta, basi ossea, parte supe-
riore cornea, non furcata, permanentia...

2. Camelopardalide.

3. Antilocapride.

4. Bovide.

d". Cornua ex osse frontali orta, omnino ossea, decidua... 5. Cervida.
e". Cornua nulla, dentes canini marium exserti
6. Moschide.

0-0

b. Placenta diffusa. Stomachus tripartitus; dentes primores, 3-3

1-1

6-6

canini molares pedes tetradactyli; cornua nulla 7. Tragulide.

In conclusion the author called attention to the geographical distribution of the Ruminants, as shown in the subjoined Table, in which the geographical divisions employed were the same as those used by the author in his paper on the distribution of Birds*, but which he believed to be equally applicable to the class of Mammals.

On the Distribution of Mosses in Great Britain and Ireland as affecting the Geography and Geological History of the present Flora. By JOHN SHAW.

Notes on the Structure of the Echinoidea regularia, with Special Reference to their Classification. By C. STEWART.

On the Traces of an Irish Lake Dwelling, found by Captain L'Estrange, in the County of Cavan. By W. TENNANT.

On a Remarkable Mode of Gestation in an undescribed Species of Arius.
By Professor W. TURNER, M.B., F.R.S.E.

In this paper a new species of Arius, from Ceylon, which the author named A. Boakeii, after the Rev. Barcroft Boake, of Colombo, Ceylon, by whom it was first sent to this country, was described. This fish lays eggs about the size of small bullets, which the male fish takes into his mouth and retains there until the young are ready to leave the egg. About twelve eggs come to intra-ovarian maturity at one time, which is the number that the male can hold in his mouth. Although Messrs. Wyman, Günther, and Agassiz have described American fish which have the same habit, this is the first specimen of a fish of the Old World in which this remarkable mode of incubating the ova has been observed. The paper, with various anatomical and zoological details, is printed in extenso in the 'Journal of Anatomy and Physiology,' November 1866.

On Reversed Sexual Characters in a Butterfly, and their Interpretation on the Theory of Modifications and Adaptive Mimicry (illustrated by specimens).. By A. R. WALLACE.

The author exhibited a Malayan butterfly (Diadema, n. sp.) the male of which was of a dull brown colour, while the female was richly glossed with metallic blue -colours which in all the allied species are characteristic of the male sex. He then showed that the female butterfly so closely resembled the very common Euplaa midamus that it could not be distinguished from it on the wing. The Euplææ, and the whole family Danaide to which they belong, as well as the Heliconidæ of South America, are protected groups, and are the subjects of imitation by many other butterflies and moths. The special protection the Danaida possess was supposed to be their very strong and peculiar odour, which rendered them distasteful to insectivorous birds; and the reason why the female only of the Diadema had acquired protection by closely resembling the Euplaa was, because in all insects the female is of more importance than the male, and it is necessary, in order to ensure the continuance of the race, that her life should be preserved while she is engaged in depositing her eggs. This was held to be a crucial instance of the truth of the Darwinian hypothesis; as what appeared at first sight a strange and unaccountable anomaly, was shown to be under certain conditions the necessary consequence of the "preservation of favourable variations in the struggle for life."

The Poor Man's Garden. By N. B. WARD, F.R.S.

On some points in the Structure of Limulus, Recent and Fossil.
By HENRY WOODWARD, F.Z.S., F.G.S., &c.

In this communication the author pointed out that although the classification proposed by Professor M'Coy for Limulus, Belinurus, and Eurypterus in 1849 was founded upon very imperfect data, yet subsequent researches tended to show that a near relationship did exist between the Xiphosure and the Eurypterida.

Mr. Woodward cited the published observations, descriptions, and figures of species belonging to these two groups, by Professors Agassiz and Hall (in America), Dr. Nieszkowski (in Russia), Professor Huxley and Mr. J. W. Salter (in England), and Mr. W. H. Baily (in Ireland), and he likewise referred to his own investigations in confirmation of his views.

The author entered at some length into the anatomical structure of Limulus, Belinurus, Eurypterus, Stylonurus, Pterygotus, Hemiaspis, &c., in order to show that by a series of intermediate forms which have of late years become known, he was able to reconcile the apparently wide diversity existing between Pterygotus and Limulus; and he submitted that they may appropriately form two subdivisions of the order Merostomata of Dana.

These views have since been published by Mr. Woodward at length in the Quart. Journ. Geol. Soc. London, vol. xxiii. (No. 89, Feb. 1, 1867, p. 28) with illustrations. See also monographs of the Palæontographical Soc. for 1865 (Dec. 1866), Pt. I. of the Merostomata.

Notes on Lithosia caniola. By Dr. E. PERCEVAL WRIGHT, F.L.S.

This species was discovered by Mr. Barrett on the Hill of Howth, near Dublin, in 1860 so very local was its habitat that it might be said to be found only on one closely sheltered bank on the south side of the hill. Since 1860, many specimens have been taken by Mr. Birchall, Mr. Dunlop, and the writer; and the limits of the species, so far as Howth is concerned, would seem to be on the increase. How this South European insect obtained a settlement on one point of the Irish coast and in no other part of the British Islands, was, Mr. Birchall confessed, a curious problem, which he ventures to solve, by supposing it may have been introduced in the larva state among moss and lichens. In the spring of 1866 Dr. Wright was botanizing on the coast of Waterford, when he was struck by the close similarity in appearance between certain portions of the Tramose strand, and that where the L. caniola was found at Howth: it had the same aspect, the same plants, and was just the place where one would expect to find the species; but it was too early in the season for it. In the course of the summer Dr. Wright requested his brother to collect all the Lithosia to be met with at the place; and, as he had anticipated, L. caniola was among them; one of the specimens was slightly different from the ordinary form of Caniola. In addition to adducing this new locality for this insect, Dr. Wright mentioned his belief that L. caniola was little more than a climatal variety of such a form as L. complanula.

Botanical Notes of a Tour in the Islands of Arran, West of Ireland.

By Dr. E. P. WRIGHT, F.L.S.

The islands consist of limestone, forming on their western sides high frowning headlands, and on those facing Galway Bay a series of coarse shingly beaches, interrupted here and there by several sandy bays. The surface of the larger island presents the appearance of a series of gigantic tombstones arranged in vast tiers, the interspaces between the large slabs of stone and the faces of the terraces containing almost all the plants to be found on the island. Dry stone walls abound everywhere, sometimes enclosing plots of ground only a few feet square; and by the help of these enclosures some few crops are sown and garnered. In some cases the potatos are planted on the bare rock, and covered over with a basketful of earth and seaweed; in others the rock gets covered over with a thin sod, which supplies a precarious nourishment to a few sheep brought from the mainland. Dr. Wright stayed eleven days on the island, visiting now and then the middle and south islands. The weather was most unfortunate, and scarcely a day passed over without rain, while a strong north-west wind, blowing with great force, made the constant jumping over stone walls particularly trying. The season was too far advanced for many of the characteristic Arran Island plants; still a sufficient number of interesting species were met with. Dr. Wright first enumerated the list of species actually collected, for convenience of reference using the nomenclature of the Cybele Hibernica' of Dr. Moore and A. G. More, the publication of which, though too late this year to do much for Irish botany, would, he doubted not, mark a new era in the investigation of this subject. He next proceeded to mention those plants which might be considered remarkable or rare, or which had not as yet been recorded as found in the district marked VI., according to the scheme adopted in the 'Cybele.' Among these he alluded to the Aquilegia vulgaris, found on the northern part of the large island; Helianthemum canum, Sedum

Rhodiola, Gentiana verna, of which nothing but the leaves remained; Solanum dulcamara, Marrubium vulgare, Allium Babingtonii, found on all the islands, and very widely scattered over the large islands; Adiantum capillus-veneris, &c. Several common plants, such as Sisymbrium officinale, Cochlearia officinalis, Torilis nodosus, &c., were mentioned simply to supply the deficiency in this respect in the 'Cybele.' On the exposed western side of the island many ordinarily met with plants were remarkable for their peculiar stunted growth. Thus the samphire, which grew in the greatest abundance, was found in full flower, and yet hundreds of the plants were not more than three inches in height; and plants of Sedum rhodiola were met with scarcely more than two inches in height. In all such cases the plants were growing in the chinks between the stones. A dwarfed condition of growth was not, however, by any manner of means the rule, for under favourable conditions fronds of the Maiden-hair fern were found twenty inches in length. Specimens of Verbascum thapsus were met with nearly five feet high; and in one instance a cluster of that fine thistle, Silybum marianum, was seen three or four of the flowering-stalks of which were five feet four inches in height. Dr. Wright next proceeded to contrast the Flora of the Arran Islands with that of the coast of Clare, referring to Mr. Foot's very interesting paper on the Burren flora, in the Transactions of the Royal Irish Academy, for this purpose; and suggested that the general affinity of the flora was rather to the Clare than to the Galway coast. This would at first sight be expected, seeing that Arran is, geologically speaking, but an extension of Clare. Almost every plant met with on the islands is met with in the Burren district, and vice versa, whereas many plants are met with in the Connemara district which are not found either in Clare or Arran. The inhabitants are indebted altogether to the mainland for their supply of fuel; and the turf which they chiefly use is brought from the immediate neighbourhood of Roundstone and Birterbuie Bay. To this circumstance Dr. Wright was inclined to ascribe the appearance of some few plants which were found very plentifully about the villages of Kilronan and Kilmeany, and yet not at all inland, such as Coronopue didyma, Urtica urens, &c. In conclusion, Dr. Wright trusted that these notes, made under very disadvantageous circumstances, might not be without some interest. Every one, he thought, was bound to contribute what he could (no matter how small that contribution might be) to make our knowledge of the Flora of Ireland complete.

PHYSIOLOGY.

Address by Professor HUMPHRY, F.R.S.

It is, I feel, no small honour to be called upon to preside over this section, which represents the very highest branch of physical science. I say the highest branch of physical science, because it has to deal with the highest and broadest of physical problems. The animal frame, which it is our work to investigate, stands at the summit of the great physical cone, with man at the apex, by whom it is, as it were, slung from heaven, in whom the material is worked up to the point of contrast with, and made subservient to, the purposes of the spiritual. Indeed so complex is the animal organism, so intricate and varied are the questions in physiology, that it is apt to pass out of the range of science, and become too much a matter of speculation and an object of mystery; so that there is some danger of its being degraded by the very difficulties and features which should really place it in the highest position among sciences.

Infinitely varied in its forms and structure, suited to every conceivable condition, where air, moisture, and heat are present, yet developed from one simple type, composed of various elements combined in the most intricate manner with endless modifications of mechanical, chemical, and electrical processes, besides others which it is scarcely possible to recount or observe, much less to comprehend, and which we group under the term "vital," the animal machine presents interests for every mind, puzzles for every genius, and challenges the whole army of science and philosophy through all coming ages to concentrate their fire and attempt even their 1866.

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