of the Eolidæ contains at its extremity a small ovate vesicle, communicating, through the biliary sac, with the digestive system, and opening externally by a minute aperture at the end of the papillæ. This vesicle is found crowded with compact masses of thread-cells; which masses, in Eolis nana, consist of aggregations of small and large thread-cells, identical in size and shape with those of Hydractinia,-on which this Eolis preys, not contained in capsules, but cemented together by mucus. When we consider that each of the vesicles is in indirect communication with the stomach, I think we may, without presumption, suggest that the masses of thread-cells found in Eolis nana are quasi fæcal collections of the thread-cells of Hydractinia, which, protected by their strong coats, have escaped the digestive process. In corroboration of this view, I may mention that the thread cells of Eolis papillosa, as figured in the work of Alder and Hancock, have a perfect resemblance to those found in the Actinias, which last animals furnish an Abyssinian repast to these carnivorous mollusca." Dr Wright afterwards found that, as to the above idea, he had been anticipated by his friend Mr Gosse, who, in his "Tenby," after noticing the existence of the thread-cells in the papillæ, remarks:-"The inquiry I suggest would be, How far the presence of thread-cells might be connected with the diet of the mollusc? And whether, seeing the forms of the missile threads vary in different genera of zoophytes, the forms of the corresponding organs in the papillæ of the Eolides would vary if the latter were fed exclusively first on one and then on another genus of the former." He afterwards found that Mr Huxley had also doubted, previously to Mr Gosse and himself, whether the thread-cells of the Eolidæ were not adventitious. Here were three independent observers to whom the idea has suggested itself; Mr Huxley had first hinted it; Mr Gosse suggested it, and how it might be found to be true; Dr Strethill Wright also had suggested it, and given two instances in corroboration of his opinion, and to-night he proceeded to detail observations which would, he hoped, entitle it to be enrolled as a proved fact in the records of science. 1st, A specimen of Eolis nana was brought home from Morison's Haven, on a shell covered with Hydractinia, taken from a rock-pool, in which was a profuse growth of Campanularia Johnstonii. The papillæ of this Eolis contained the two kinds of thread-cells which are found on Hydractinia, together with the large thread-cells which occur within the reproductive capsules of C. Johnstonii. 2d, An Eolis coronata was taken at Queensferry, on a massive specimen of Coryne decipiens, which was very abundant there. The thread-cells of C. decipiens were very distinctive, being very large, oval, and containing a four-barbed dart. The thread-cells of the Eolis and Coryne were carefully compared together, and were found to be identical. 3d, Dr M'Bain and Dr Wright found an Eolis Drummondii on a fine specimen of Tubularia indivisa. They first carefully examined

the thread-cells of the Tubularia, and found four kinds, two (large and small) of a nearly globular shape, each containing a four-barbed dart, and two (large and small) of an almond shape, the larger one containing a thread, furnished with a lengthened brush of recurved barbs. They then examined the papillæ of the Eolis, and found the ovate sacs filled with an indiscriminate mixture of all the four kinds of thread-cells found on Tubularia indivisa. 4th, Dr M'Bain and Dr Wright found a specimen of Eolis Landsburgii on Eudendrium rameum. Eudendrium rameum was furnished, as to the bodies of its polyps, with very large bean-shaped thread-cells, in which an unbarbed style could be detected, while the tentacles of the polyps are covered with exceedingly minute cells. They compared the thread-cells of the Eudendrium with those found in the sac of Eolis, and found both kinds identical. Lastly, Dr Wright had kept the specimen of Eolis Drummondii above-mentioned fasting for a long time, and then introduced it to a large specimen of Coryne decipiens fresh from the sea. The next morning every polyp of the zoophyte had vanished, and the ovate sacs of the Eolis were packed with the distinctive thread-cells of the Coryne, mixed with a few thread-cells of T. indivisa, the remains of its former feast. He also found the thread-cells of C. decipiens in the alimentary canal. It was at one time supposed that thread-cells, or Cnidæ, as Mr Gosse had named them, were only to be found in the hydroid and helianthoid polyps and the Medusa; Professor Allman afterwards discovered them in a species of Loxodes, a protozoan animalcule; and Dr Wright had the good fortune to find them on the tentacles of an annelid, Spio seticornis, and also on the tentacles of Cydippe, one of the Ctenophora. Since then he had observed them on the very minute tentacles of Alcinöe, another of the Ctenophora. In all these classes of animals thread-cells were developed within the ectoderm or skin of the animal, and in many, such as in T. indivisa, each within a distinct and very apparent sac, and not in connection with the digestive system. The type of structure, moreover, of the thread-cell in the Protozoon, the Polype-medusa, the Annelid, and the Ctenophore, was essentially different for each class; and this fact alone would lead one to doubt as to the origin of the thread-cells of Eolis, which so exactly resembled those of the polype-medusæ in their structure. Nevertheless, it was certainly a very strange fact, for a fact the author firmly believed it to be, that one animal should be furnished with apparatus for storing up and voluntarily ejecting organic bodies derived from the tissues of another animal devoured by it, and that these should still retain their destructive functions unimpaired; and he stated that his friend Mr Alder, one of the highest authorities on the Nudibranchs, still hesitated to assent to the doctrine sought to be proved by the present communication, on the ground of its extreme improbability.

III. Notice of a Skull of the Troglodytes Niger, Desm., the Chimpanzee, found in a "Devil-house," Old Calabar, Africa. By JOHN ALEXR. SMITH, M.D.

The skull on the table was one of those interesting objects of natural history, for the exhibition of which the Society is indebted to the zeal of our Treasurer, Mr William Oliphant, and, through him, to the missionaries of the United Presbyterian Church at Old Calabar. It was sent home by Mr Archibald Hewan, the Mission surgeon, and was entitled by him the skull of an ape, taken from an old "devil-house" at the Guinea Company's villages, about a hundred miles from the mouth of the Old Calabar River. It is the skull of an adult Chimpanzee, indicated by its general appearance, the calvarium smooth and rounded, the partially obliterated sutures, and the full complement of teeth, well ground down on their summits. These teeth are similar in number to those of man. The skull measures 19 inches in circumference, in the line of the alveolar processes of the incisor teeth in front, and the occipital protuberance behind; and rather more than 7 inches in length between the same points in a straight line. The skull of an adult male is described as measuring 8 inches in length; this is probably therefore the skull of an old female,-the muscular ridges being but slightly marked; the space between the incisor teeth and the canines is very slightly developed, measuring little more than 1-10th of an inch. The characteristic high superciliary ridge of the Chimpanzee is strongly marked; showing at a glance the very vague character of any deductions as to the amount of brain, to be drawn from the extent of what is called the facial angle in a cranium such as this. This formidable animal stands some 3 feet 10 inches high, the male reaching the height of 4 feet from the top of the head to the sole of the heel in a straight line. You are aware these creatures have been frequently described. as reaching a much higher stature (it was believed with increasing age), but it now appears from the recent researches of naturalists, both in America and in this country, that there are at least two distinct species of Chimpanzee, inhabiting in one instance the same district of country, one of which is much larger than the other. The cranium now exhibited be

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longs to the smaller species. The larger, the Troglodytes gorilla, stands 5 feet high and upwards. The T. Niger is found in various parts of the western coasts of tropical Africa, as the Guinea coast and Angola, and also between these distant places, as in this instance on the Calabar River, thus showing a pretty extensive range. The large Chimpanzee, or Troglodytes gorilla, has been brought from the neighbourhood of the Gaboon River, nearly under the Line, where the T. niger has also been procured; but future inquirers will probably give the former also a much more extended range, as the huge Chimpanzees, said to have been seen in various parts of western tropical Africa, will probably turn out to be the gorilla; and what have been supposed to be merely exaggerated tales may thus have more truth in them than we have been inclined to give the narrators credit for. The killing of one of those formidable creatures is considered a great feat by an African brave; and in this instance, apparently, the skull had been preserved as of great value, if not also for worship. You observe there is a piece of copper wire, 1 foot 11 inches long, and 2-10ths of an inch thick, which is wrapped twice in a vertical direction round the skull, passing through the temporal fosse of each side, behind the superciliary ridge above, and the nasal fossæ below. Hammered copper wire is the current money of this part of Africa; so the amount of metal used in ornamenting this skull shows the high value the owner had placed on it. It was taken, I have already mentioned, from what is called a devil-house, for a certain amount of English is spoken by many of the native chiefs. and traders. This devil-house, as I have been informed by Dr Sommerville, Secretary to the Mission Board of the U. P. Church, is not, strictly speaking, a place of worship. It is, like their dwelling-houses, built of branches of trees and clay, and is erected at the death, especially, of a great man; after various ceremonies have taken place, and, in former times at least, the sacrifices of human beings, sometimes to the number of hundreds, according to the rank of the deceased-the slain being supposed to be thus sent as his slaves and attendants to the other world-their remains are buried in one common tomb, and over it this devil-house is

erected; it is left open at one end, and in it the valuables of the deceased are placed-his furniture, clothes, utensils, and food. These, however, are shortly after, more or less damaged or broken, for one of two reasons, if not for both-either to kill the articles themselves (for in Calabar all things are supposed to possess life), that their spirits may go to benefit the spirit of the deceased, or, to prevent people from sacrilegiously stealing them. The whole being intended as an offering to the fetish, or evil spirit, and left as sacred to the memory of the deceased. As in other parts of Heathendom, an evil spirit is worshipped, as well as a good spirit; and fear, which is the moving principle of their worship, naturally makes more respect be paid to the bad than to the good, the vengeance of the former being most feared, and therefore greater pains are taken to propitiate his anger. The principal fetish, or evil spirit, worshipped in the houses of Old Calabar is, strange to say, a human skull without the lower jaw, which is tied by bands of plaited leaves, crossing one another, to the top of a thick block of wood, the upper part of the rounded stem of which is also. wrapped about with bands of plaited leaves or thongs. Dr Sommerville kindly showed me one of these in his possession. We may therefore suppose this skull of the T. niger had been offered as a highly valued propitiatory offering to the fetish, if not also worshipped as the representative of the much-feared fetish or evil spirit itself in the home of the man from above. whose grave it was taken.

Crania of the two species of Chimpanzee are described by Professor Owen in the Transactions of the Zoological Society of London. Captain Wagstaff, who brought them to Bristol, stated "that the natives, when they succeed in killing one of these Chimpanzees (the gorilla), make a fetish of the cranium. The specimens bore indications of the sacred marks in broad red stripes, crossed by a white stripe, which could be washed off. Their superstitious reverence of these hideous remains of their formidable and dreaded enemy adds to the difficulty which a stranger has to contend with in procuring specimens." This quotation shows how general is the feeling of superstitious dread which appears to exist with regard to these Chimpanzees, creatures, which of all the lower animals, in their structure and general appearance, make the nearest approach to man.