silicle, that is, according to this explanation, to the apex of the enveloping leaves. The term "false" dissepiment is therefore no longer necessary, the fruit being a normal growth, though of an unusual construction. On the Species of Grimmia (including Schistidium) as represented in the neighbourhood of Edinburgh. By J. SADLER. Observations on the intimate Structure of Spiral ducts in Plants and their relationship to the Flower. By NEIL STEWART. An Inquiry into the Functions of Colour in Plants during different Stages of their Development. By NEIL STEWART. On the Classification of the Vascular Cryptogamia, as affected by recent Discoveries amongst the Fossil Plants of the Coal-measures. By W. C. WILLIAMSON, F.R.S., Professor of Natural History in Owens College, Manchester. The author described the structure of the stem of Calamite explaining, his interpretation of its structure, viz. that it consisted of a central fistular medulla, surrounded by a ring of woody wedges, each one of which grew by additions to the exterior of its surface until it often became a woody cylinder of considerable thickness. The Lepidodendra and Sigillaria were next reviewed, beginning with Lepidodendra, in which the central axis was a mixture of cells and vessels surrounded by a very thin, and often scarcely appreciable ligneous ring, and which gave off vascular bundles to the leaves. Other forms were then noticed in which the central medulla became differentiated into a central cellular portion, and an outer vascular one, the latter existing as a modified medullary sheath. One of the types described by Mr. Binney as Sigillaria vascularis, exhibits these features; and the development was traced still further through Diploxylon and Sigillaria, where the woody zone became yet more fully developed, the medullary rays more distinct, and the differentiation of the two elements of the pith, viz. the vascular and the cellular, yet more complete. The origin of the vascular bundles going to the leaves in some forms of Diploxylon was shown to be, not in the medullary vessels, as described by Corda, but in a cellular layer separating the ring of the medullary vascular cylinder from the more external vascular cylinder of the true woody zone. The relation of these various structures to those seen in Stigmaria was pointed out. In the latter, as was to be expected in a root, the vessels of the medullary axis disappeared, the pith being in direct contact with the inner surface of the woody zone. The vascular bundles given off to the rootlets were shown to originate in the ligneous cylinder, and to pass outwards through large lenticular spores, occupied by mural cellular tissue, separating the woody wedges, whilst in addition to these spores, there exist a complete system of minor medullary rays, the entire structure exhibiting, in the author's opinion, an exogenous arrangement. The conclusion to be drawn from the study of the structure of these fossil cryptogamic stems is, that, so far as their medullary axis and ligneous zone is concerned, they are not in any sense Acrogens, but Exogens; that they have a pith consisting of the less developed Lepidodendroid forms of a mixture of cells and vessels; that as we ascend in the series of forms the cells become separated from the vessels, the former occupying the interior, and the latter the exterior of the medullary axis; that the woody zone surrounding the medullary axis consists of a cylinder composed of radiating lines of vessels, which increase by successive additions to the external surface of the zone, the lamina of which vessels are separated by mural arrangements of cellular tissue constituting two kinds of medullary rays; consequently when such a process of growth has gone on until the result was a tree with a stem two, three or more feet in diameter, the application of the term acrogen becomes absurd. Such being the case, Prof. Williamson proposed to separate the vascular Cryptogams into two groups. The higher one, comprehending the Equisetaceae, Lycopodiaceae, and Isoetaceae, to be termed the Cryptogamiæ Exogenæ, and which would form a connecting link between the Cryptogams and the true Exogenous plants through the Cycades, and the other Gymnospermous Exogens. The lower one to be called the Cryptogamia Endogenæ, to comprehend the Ferns, which will unite the Cryptogams with the Endogens through the Palmaceæ. ZOOLOGY. Notice of two Specimens of Echinorhinus spinosus taken in the Firth of Forth. By Professor J. DUNS. On the Rarer Raptorial Birds of Scotland. By Professor J. DUNS. On the Carabus nitens of the Scottish Moors. By Dr. GRIERSON. The Zoological Results of the Dredging Expedition of the Yacht Norna' off the Coast of Spain and Portugal in 1870. By W. SAVILLE KENT. The expedition was organized and superintended by Mr. Marshall Hall, the owner of the yacht, Mr. Kent accompanying him to supervise the collection and preservation of natural-history specimens, as also to report on all the novelties or objects of interest that might be obtained. The sponges collected during the expedition appear to have furnished the greater number of forms new to science, embracing more particularly many new representations of the group to which the beautiful Euplectella, or "Venus's flower-basket," and the " Glass-rope sponge," Hyalonema, belong, the latter, indeed, being amongst the spoils. All these forms were dredged in the deep-sea fishing ground, 400 to 800 fathoms, off Cezimbra, at the mouth of the Sado river; and from the same locality, with the assistance of the native fishermen, they had the good fortune to secure examples of several rare species of deep-sea ground sharks which frequent that coast line, including among others Pseudotriakis microdon, a species recently described by Professor Barboza du Bocage, of the Lisbon Museum. Fusus contrarius and a species of Cassis allied to C. saburon are among the rarer shells referred to by Mr. Kent, the former being interesting on account of its identity with a common fossil of the Norwich Crag, and the latter from its affinities with Japanese and Chinese species rather than with any known Atlantic or Mediterranean form. The occurrence in the same waters of a variety of Hyalonema, scarcely to be distinguished from the well-known Japanese H. Sieboldi, is also commented upon by Mr. Kent, as illustrating another instance of this singular distribution of allied species. Reviewing the whole amount of material collected during the cruise, Mr. Kent separates it into two portions, presenting respectively two entirely distinct facies. The first of these, including that collected from the shore line down to a depth of 100 fathoms, presents an interblending of Mediterranean species with those inhabiting our own more temperate coasts; while the remaining one, embracing all those acquired at a depth of from 400 to 800 fathoms, are remarkable for their boreal or cold-water area aspect and affinities, and in this respect, according to Mr. Kent, entirely supporting the deductions arrived at by Dr. Carpenter, from his extensive study of the fauna of these great depths in connexion with the expeditions of the 'Lightning' and 'Porcupine. Among the more interesting Mediterranean forms taken, especial mention is made of Dendrophyllia ramea, a massive branching coral, not before recorded as occurring so far north, as also of various species of Murex, Calappa granulata, Cestum veneris, and other zoophytes usually supposed to be restricted to the more southern arc. Mr. Kent expresses his hope that the entire success attending this cruise may influence other yacht-owners to follow the example of Mr. Marshall Hall, and, like him, to devote their craft for the portion of a season to scientific discovery, promising them they will find themselves more than compensated for the sacrifice of time or other interests it may involve by the fascinating nature of the work when entered upon, in addition to their thereby earning for themselves the lasting gratitude of the scientific world. The Royal Society granted £50 towards aiding in the necessary outlay in dredging and preserving apparatus. The paper constitutes a brief sketch of a report to be presented to the Royal Society by Mr. Kent. A Proposal for a Modification of the strict Law of Priority in Zoological Nomenclature in certain cases. By W. A. LEWIS. On some recent Additions to the Arctic Fauna (a new Antipathes and a new Apodal Lophioid). By Dr. CHRISTIAN LÜTKEN. On the occurrence of Brown Trout in Salt Water. In the sixth volume of his Catalogue of Fishes (Addenda, page 357), Dr. Günther has noticed the fact that Salmo fario frequently descends to the sea, and there "assumes a bright silvery coloration, with numerous x-shaped spots." The circumstance did not, however, seem to have met with so much attention as it deserves, and was very little known to anglers and fishermen. In Scotland, Mr. Peach, who had an extensive experience and knowledge of marine zoology, had assured him that no instance of the kind had come under his notice, save once, when he found a river-trout in the stomach of a cod-fish. But in the west of Ireland (in the counties of Donegal, Sligo, Limerick, and Kerry) Mr. More had ascertained, partly through others and partly from his own observation, that the river-trout in many places spontaneously frequents the salt water at the mouth of the rivers. The brown trout captured in salt water differ from their usual condition in having brighter and more silvery scales, something like those of the young salmon in the smolt condition; but he had not noticed any increase in the number of dark x-shaped spots. Mr. More would like it to be ascertained if these trout were brown trout "pure and simple," or hybrids. Specimens were exhibited. On some Dredgings in Kenmare Bay. By A. G. MORE, F.L.S., M.R.I.A. Mr. More exhibited a number of marine animals, which he had lately collected in Bantry and in Kenmare Bays, in the south-west of Ireland. Among them were Amphioxus lanceolatus, the lowest in organization of living fishes, a number of Annelida and Ascidians, &c. On the so-called Tailless Trout of Islay. By C. W. PEACH, A.L.S. Mr. Peach stated that the trout he showed were sent to him by Mr. Colin Hay, distiller, of Ardbeg Islay, taken in Loch Namaorachin, about 1000 feet above the level of the sea; it is supposed to be the highest in the island. It is about an acre in extent, and so shallow that a man can wade through it; the bottom is quartz rock, like that of the mountains around it. Several other lochs are near it in which trout are plentiful, but none "tailless." So constant is this that Mr. McKay, a very keen fisher, has never for the thirty years of his fishing-experience in this loch taken any but "docked" ones. Mr. Peach further said that Mr. Hay was about to stock a loch at some distance from Loch Namaorachin with some of the "tailless" trout, in which, up to the present time, no trout have been taken, and thus to try whether this "docked" appearance will continue, and use other means to work out as far as possible the history of this strange freak. He added that they could not be called altogether "tailless;" docked they may be, from not having a vestige of the external caudal fin-rays. The fish were in splendid condition, and the whole of the other fins perfect; and in every other respect nothing was wanting, as could be seen by the specimens shown, and by the beautiful skeleton of one prepared by Mr. Stirling, assistant to Professor Turner*. On the Hydrographical System of the Freshwater Fish of Algeria. Remarks on a favourable occasion for the establishment of Zoological Observatories. By P. L. SCLATER, M.A., Ph.D., F.R.S. After alluding to the report of the Committee of the British Association for the establishment of zoological observatories, which had been read by the author at a previous meeting of the Section, attention was called to the fact that a very favourable opportunity for the establishment of three zoological observatories in very little-known parts of the globe would shortly present itself, and it was greatly to be hoped that advantage would be taken of it." On the occasion of the transit of Venus in 1874, the Astronomer Royal proposes to organize observing-expeditions to the following five stations:-(1) Õahu, Sandwich Islands, (2) Kerguelen's Island, (3) Rodriguez, (4) Auckland, New Zealand, (5) Alexandria. At the first three of these stations (Oahu, Kerguelen's Island, and Rodriguez) it would be necessary to have a corps of scientific observers resident for twelve months previous to the transit, in order that the absolute longitudes of these places, which were not correctly known, might be obtained. The author pointed out how little was yet known of the terrestrial and marine zoology of these three islands, and specified various particulars, in the case of each of their faunas, which it would be especially desirable to investigate. He then urged that the addition of one or more zoological collectors, or observing-naturalists, to the corps of astronomical observers in each of these stations would occasion very slight additional expense, and suggested that application should be made to the Government to permit such naturalists to accompany these expeditions, and to undertake the necessary expenditure. Dr. J. A. SMITH exhibited the Skull of an Elk found in Berwickshire. On the Structure of Crinoids. By Professor WYVILLE THOMSON, F.R.SS. L. & E. On the Paleontological Relations of the Fauna of the North Atlantic. On a curious South-African Grasshopper, Trachypetra bufo† (White), which mimics with much precision the appearance of the stones among which it lives. By ROLAND TRIMEN, F.L.S., F.Z.S. He commenced by remarking that some tendency existed to separate too widely those cases of mimicry where one animal imitated another, from those * Since the paper was read Mr. Peach had learnt that this want of caudal fin-rays has not been occasioned by lead-poisoning; for not a particle of lead is to be found in or near the loch. In a loch on the island about 6 miles from Loch Namaorachin trout are found plentiful; this loch is in a limestone basin, and lead is abundant in it; and here all the trout have perfect tails, and all the other fins in fine condition. + Methuen's 'Wanderings in the Wilderness,' 2nd edit. 1848. Appendix, p. 362, pl. ii. f.3. in which an animal closely resembled either some part of a plant or some inorganic object; and expressed the opinion that these two sets of cases were wholly one in kind, the evident object in all being the protection of the imitator. Describing a visit paid to the vicinity of Grahamstown in search of this insect, he observed that it was a work of considerable difficulty to distinguish the grasshoppers from the stones, and he was engaged for half an hour in careful search over a known station of the species before discovering an example. He noted the further most interesting fact, that, in certain spots (often only a few square yards in extent) where the stones lying on the ground were darker, lighter, or more mottled than those generally prevalent, the Trachypetra found among such stones varied similarly from the ordinary dull ferruginous-brown colouring in imitation of them. It was pointed out that the close imitation of the stones was mainly effected by the modification of the dorsal shield of the prothorax, which is (with the whole thorax) much flattened and widened, and is further much produced posteriorly, and has its surface roughened or granulated in close resemblance to the surface of the stones. In conclusion, he called attention to the bearing of the case of this insect on the question of the origin of species; and in putting the alternative whether the peculiar station of the Trachypetra had been specially prepared for it immediately before or simultaneously with the creation of the insect, or whether, on the contrary, the insect had been very gradually modified by natural selection in imitation of the stones for the purpose of concealment, he expressed his decided opinion in favour of the latter hypothesis. Specimens of the insect were exhibited in association with some of the stones among which they were captured; and the very close resemblance between the stones and the insects was very obvious. Mr. Trimen observed that in nature the mimicry was more effective, the colours of the dead insects having faded considerably, and the shrinking of the abdomen having caused the hind legs to be much more apparent than was the case in living examples. Les Chauves-souris de l'époque du Mammouth et de l'époque actuelle. La théorie de Darwin est, dit-on, une véritable conception scientifique, fondée sur la concurrence vitale et la sélection naturelle. L'évolution naturelle des formes est pour le savant illustre le résultat de la lutte pour la vie et de la survivance des plus forts. Si les animaux subissent la loi de cette concurrence vitale et de la sélection naturelle, il faut se demander quel est l'effet de cette influence pendant la période actuelle. Pendant ce long laps de temps qui nous sépare de l'âge du Mammouth et de l'Ours des cavernes, quelles sont les modifications qui sont survenues dans le nombre comme dans les caractères des espèces? S'aperçoit-on des effets de la lutte pour la vie et, comme conséquence, de la survivance des plus forts? C'est la question que nous avons voulu examiner. On est généralement d'accord sur ce point que, pour expliquer les phénomènes des temps géologiques, il faut chercher la solution dans les phénomènes de l'époque actuelle. Ce qui se passe sous nos yeux doit nous faire comprendre ce qui s'est passé antérieurement. C'est cette pensée que vient d'exprimer avec tant d'élégance l'illustre Président de l'Association, Sir William Thomson, dans son discours d'ouverture: L'essence de la science consiste à déduire de phénomènes actuellement soumis à l'observation l'état antérieur des choses, et à préjuger leurs évolutions futures. Nous avons été conduit à nous occuper de ces questions à la suite de recherches sur les parasites des Cheiroptères (Chauves-souris) et d'explorations faites dans les cavernes. Nous avons comparé des animaux, vivant autour de nous et dans nos grottes, avec ceux qui hantaient autrefois ces mêmes lieux à l'époque où les Ours et les Rennes remplissaient ces retraites de leurs dépouilles. L'on sait que les ossements qui sont enfouis avec ceux des Ours appartiennent à trois catégories d'animaux: la première comprend ceux qui ont disparu de nos |