diately following, statement, that "dans le homard. 66 les “ pédicules oculaires se développent plus tôt et indiquent plus clairement que chez les Mysis leur communauté d'origine avec les organes appendiculaires." It appears, therefore, as is indeed directly stated in p. 29, that in spite of some confusion of expression in p. 62, Professor Van Beneden does, in fact, consider the ocular pedicule as the appendage of the anterior segment. He also regards the "telson" as representing a posterior segment, and adopts, therefore, Milne Edwards' view, that the body of a Crustacean consists of twenty-one segments, in opposition to those naturalists who see only twenty. So accustomed are we to see the organs of sensation located in the head that we cannot but feel astonished to find that the ear of Mysis is not in its head, but in its tail. This curious fact, which was discovered by Leuckart, has been confirmed by several distinguished naturalists, and last, not least, by M. Van Beneden, who moreover, like Kröyer, has traced a nerve from the last ganglion to the otolithe. We may find a parallel case in the little worm described by Quatrefages, under the name of Polyophthalmus, which has eyes on every segment of the body. Amphicora Sabella also, another worm, has, according to O. Schmidt, eyes in its tail. Moreover, among insects, the Crickets and Grasshoppers have an organ in the anterior pair of legs, which is considered by some good observers to be an ear, but which certainly is, like the remarkable organ at the base of the halteres of Flies, an organ of some special sense, though what that sense may be it is not so easy to decide. The Professor does not always do justice to his predecessors. Thus under the Cetochilidæ he refers only to Roussel de Vauzème and Goodsir, entirely ignoring all that has since been written on this family. He mentions only one species belonging to the group, and this one he attempts to identify with the Cetochilus septentrionalis. His description of it, however, clearly shows that it does not belong to this family of Entomostraca at all, but is one of the Calanidæ, and belongs probably to the genus Calanus, which may at once be distinguished from Cetochilus by the position of the eyes. Many of the Calanoidea have at the anterior extremity of the cephalothorax two curious horns, which were mistaken by Goodsir for antennæ. Professor Van Beneden corrects this error, which, however, was pointed out long ago by Baird, and has been adopted by no subsequent writer. The description which he gives of the different parts is almost useless for identification, as the characters mentioned are those which are common to many species: take away the extremities of the antennæ (antennules of V. Beneden), those of the abdomen, and the posterior pair of legs; half the species of Calanus would be undistinguishable from one another. Of this our author was evidently not aware, and his attention has not been particularly drawn to the characteristic organs. Moreover, we cannot supply the deficiencies from the plate. He gives three very dissimilar representations of the antenna; two of them, however, are small, and perhaps, therefore, not intended to be strictly accurate. Unfortunately, however, this is not the only error. In his two figures of the animal the proportions of the segments are different, the anterior cephalothoracic segment being absolutely longer in the smaller figure. It is, indeed, difficult to believe that the two drawings have been taken from the same species, as the abdominal segments differ not only in proportion but in number, and the length of the antennæ is by no means the same. Again, the abdomen, as represented in figure 5, differs from that either in figures 1 or 7, agreeing, indeed, with figure 7 in the number of segments, but differing in their proportion as well as in the form of the caudal lamellæ and the number of the caudal setæ. Still, the drawings are good, and apparently truthful. Some of the differences above alluded to (and which are by no means all that might have been pointed out) may be sexual characters; some may be the result of mutilation; but there are others which cannot be accounted for in this manner; and as there are many species of this group which are at first sight very similar to one another, we suspect that in Professor Van Beneden's Plate xviii., and in his description, two or more species have been confounded together. The pretty little Isopod, originally described by Slabber under the name of Agaat-Pissebet, has been rediscovered by Van Beneden, and named by him Slabberina, after its first observer. The spermatozoa of this species (Plate XV. figure 10) are, according to the figure given, in the form of a long seta with a bundle of shorter hairs at one end. If, however, we may judge from the parallel case of Asellus, these bodies are not simple spermatozoa, but we have here another case of bimorphism in the seminal elements. In our common fresh-water Asellus aquaticus, the spermatozoa are of two sorts. The first are oval, or more or less elongated bodies diverging in the form of a brush from a common point of attachment. From the same point arise several long and slender seta, which, however, are often attached together along their whole length so as to look like a single filament. We presume that the same is the case with Slabberina, and that we may add this genus, therefore, to the small but gradually increasing number of species in which the spermatozoa are of two sorts, and which are, perhaps, destined, ere long, to throw a new light on the whole subject of generation. An interesting chapter is devoted to the Sacculinida. They are parasitic on higher Crustacea, and are the most degraded of their class. The sandy shores of Ostend are inhabited by great numbers of common Crabs. Three-quarters of these carry on the underside of the abdomen a little yellow ball, which is sometimes as large as a nut, and which, of course, prevents the abdomen from fitting into its furrow. This yellow globule, at first sight like nothing less than the active lively Crab, belongs nevertheless to the same great group of animals, and forms the genus Sacculina of Thompson. A second member of the same family, the Peltogaster Paguri, attaches itself, as its name denotes, to the Hermit Crab, whose name is, indeed, a very misnomer. The so-called happy families, which we sometimes see in our streets, offer no such odd assemblages as we may often find in and on the shell of a dead whelk. First we have the Hermit Crab himself; the margin of the shell is often tenanted by a species of Anemone (Adamsia palliata), while the rest of its surface is covered by a growth of the curious and pretty little polyp, known as Hydractinia echinata. Nor is the Pagurus the only occupant of the shell. Mr. Gosse tells us of a co-tenant in the form of a beautiful Nereid worm, which, like the preceding species, feeds on the crumbs which fall from the rich man's table. "The soft and serpent-like Annelide," we quote from Mr. Spence Bate (Zoologist, 1859, p. 6687), "smells "the repast that the master of the house is enjoying, and, like a wily guest, takes care to be present at the meal, even though unbidden. "See! beneath the Crab the beautiful head glides out. While the "self-confident owner is devouring one piece, and in his full enjoy"ment looking round and, perhaps, admiring the submarine scenery, "the worm attacks that which is in the other hand, and by little and "little the Crab feels it going, and makes an effort to stop it on the way; but it evidently can be seen, by his manner, that he cannot "believe that any one would be so rude as to steal his dinner out of "his very mouth, and does not think much about the undevoured food, but which, nevertheless, is slowly, gradually, and surely taken away." 66 66 66 To this interesting group must be added the Peltogaster Paguri, which, when mature, has a regular oval form, and a reddish colour, due to the numerous eggs it contains. So little does it, indeed, resemble a Crustacean that we cannot wonder at the mistakes which have been made concerning its true nature. Cavolini regarded it as a sort of animal-gall, not recognizing it as an entire animal, but supposing that some other Crustacean deposited its eggs in the Pagurus. Thompson first described it correctly, and recognized its affinities with the Lerneida. Rathke at first placed it among the Trematodes, in which he was followed by Diesing and Dujardin, though the latter, indeed, says that it "parait être toute autre chose "qu'un trematode." Kroyer expresses no opinion as to its affinities. Steenstrup classes it with Bopyrus, among the Isopods. Lilgeborg looks upon it as a Cirrhiped. Professor Van Beneden places the Sacculinidæ in his list of Crustacea, observed on the shores of Belgium, immediately arter Lerneonema, and explains their homologies as follows: "Que l'on se figure, en effet, des Nicothoë, dont les deux poches s'étendraient tout autour du segment qui leur donne naissance, en d'autres termes, dont le segment tout entier se prolongerait en arrière de manière à envelopper l'abdomen et la queue; il y aura un orifice postérieur d'evacuation, un véritable cloaque d'oiseau; en supposant ensuite que la tête s'allonge comme dans les Lernea branchialis et plonge de la même manière dans les chair, que les segments en arrière et en avant s'effacent pour ne plus laisser place qu'en segment sexuel, nous aurons une idée de cette transformation singulière d'un animal régulier et symétrique en sac informe et gaine à œufs." 136 Original Articles. XV.-ON THE DESIRABILITY OF AN ENGLISH TRANSLATION OF ARISTOTLE'S HISTORY OF ANIMALS: by Rev. W. Houghton, M.A., F.L.S. Or all the great intellectual luminaries that have enlightened the different departments of human learning, it would be difficult if not impossible to name one that can justly claim to rival Aristotle in the extent and depth and philosophic value of his writings. The Zoologist may well feel a degree of pride when he remembers that this great man was the founder of his science; for it is to Aristotle that he is indebted for the birth of Zoology; it is he who first attempted to reduce to a system the various and diversified forms of animal life which even the limited geographical knowledge of the ancients served to make them acquainted with. Truly one stands aghast when one contemplates over how wide a field of human thought the vast mind of Aristotle wandered, and how ably and comprehensively each subject is treated. The modern zoologist, knowing well how extensive an area his own particular science occupies, devotes his time and study to acquire, as perfectly as he is able, a general knowledge of the laws of the animal kingdom, and afterwards is fain content for the most part to confine himself within some circumscribed boundary, and to give his attention towards the full and exact elucidation of some particular group; but when we think of Aristotle's labours, whether in the field of Natural Science or in that of Dialectics and Logic, we can only wonder and admire, but cannot attempt to imitate. "Had this extraordinary man," Swainson* well observes, "left us no other memorial of his talents than his researches in Zoo'logy, he would still be looked upon as one of the greatest philoso"phers of ancient Greece, even in its highest and brightest age. But "when it is considered that his eloquence and his depth of thought gave laws to orators and poets, that he was almost equally great "in moral as in physical science, we might almost be tempted to "think that the powers of the human mind had retrograded, and that "originality of thought and philosophic combination existed in a far "higher degree among the heathen philosophers than in those who "followed them." But though all the encomiums that have been passed upon Aristotle, from the time of Cicero to our own day, are justly due, when we reflect on the time in which the philosopher lived, when Science was unaided by the modern mechanical appliances which the ingenuity and skill of man has planned and executed, we must not be led into • Discourse on the Study of Natural History, p. 6. the error of supposing that Zoological science has made but little progress since the days of the Stagyrite, nor must we be unprepared to meet, in the Physical writings of our author, with many errors and fables,-much chaff mingled with the grain. The following remark of Buffon can not certainly be regarded as unimpeachable now, though it serves to show how rapid a stride Zoology has made since the days of the French naturalist :- "Aristotle's History of Animals is perhaps even now the best work of its kind; he probably knew animals better and under more general views than we do now. Although moderns have added their discoveries to those of the ancients, I do not believe that we have many works on Natural History that we can place above those of Aristotle and Pliny."-(Hist. Nat. i. p. 62.) Still though it would now properly be regarded as a mark of ignorance to compare the state of Zoological science as first promulgated by Aristotle, with its more developed though still imperfect form as it has been handed down to us by Cuvier, Milne-Edwards, Owen, and a hundred other patient workers in the same inexhaustible mine, it is nevertheless true that it was Aristotle who first taught us to look to the internal structure as the only safe guide to a natural system of classification, and who by his own anatomical investigations, to which he frequently refers, led the way in which Cuvier afterwards so successfully followed. But there is no need for me to enlarge at all on a topic with which every zoologist is familiar; the object of this paper is to call the attention of English naturalists to the desirability of having such a faithful translation of the περὶ Ζώων Ιστορίας as shall present in an accurate form the contents of that great book. The utility of such a translation must I think be evident to every student; he will find in the Treatises on Animals that some of the same problems which have engaged the attention of modern naturalists presented themselves ages before in a somewhat similar form to the enquiries of Empedocles and other ancient philosophers. Who, for instance, can fail to discern in the following passage from the De Partibus Animalium the question on the theory of development, as advocated by Lamarck and the author of the "Vestiges of Creation:"-" Similarly some philosophers assert, with respect to the generation of animals and plants, that from water flowing in the body the stomach was produced, and every organ recipient of food or excrement, and that by the passage of the breath the nostrils were burst open.' (Vol. i. p. 640, ed. Bekker.) The reader will find, again, in Aristotle, matter relating to "Spontaneous Generation," a theory which has recently been advocated by M. Pouchet* with considerable ability, and supported by many curious, though at present inconclusive results. It is desirable to have an English translation of the "History of • Hétérogénie, ou Traité de la génération spontanée, Paris, 1859, and Genèse des proto-organismes dans l'air calciné et à l'aide de corps putrescible portés à la temperature de 150 dègres. in Compt. Rend. Acad. Sc. Paris, 1860. |