306 Miscellaneous. 



cells are not at first separated by any intermediate membrane, and 

 their protoplasm is directly continuous ; so that, looking at things 

 only by their first appearance, M, Gerbe might really be justified in 

 thinking that he had under his eyes a small ovum with two lobes, 

 each containing a vesicular nucleus in a common vitelline mass. 

 But the illusion is no longer possible when these bodies have passed 

 to a more advanced stage. In fact a transverse membranous sep- 

 tum is soon formed between the two adherent daughter cells, 

 and separates their contents. This septum is visibly continuous 

 with the line of the outer contour of the two cells, and conse- 

 quently cannot be interpreted otherwise than as an internal prolon- 

 gation of the enveloping membrane, which was originally com- 

 mon to them. Thus I cannot share in the opinion of M. van Bene- 

 den, who denies a cell-membrane to the young ovules. It is by 

 means of this median septum, which, instead of splitting, and thus 

 permitting the separation of the two ovules, remains simple, that 

 the latter are, so to speak, soldered together. This splitting only 

 takes place much later, when one of the two united cells, having 

 alone continued its development, becomes transformed into a ma- 

 ture ovum, as described by M, van Beneden. We still see, for a 

 longer or shorter time, at the surface of this ovum, the ovule which 

 has remained stationary in its development in the form of a small 

 rounded prominence ; but this is detached when the ovum quits its 

 follicle to pass into the oviferous pouch. It was by following the 

 gradual development of this ovum that M. van Beneden ascertained 

 that the supposed eicatricula with which M. Gerbe had endowed it 

 was nothing but the little sister cell adhering to it, and that the 

 cellular nucleus which the same observer supposed to exist at the 

 centre of this eicatricula was only the nucleus of this same cell. We 

 arrive at a similar demonstration by the mechanical means which 

 enable us to separate these two bodies. Thus by roUing the oviim 

 carefully under a thin glass cover, we sometimes succeed in detach- 

 ing from it the little ovule, which, as soon as it is free, resumes its 

 original spheroidal form. The same result is also sometimes obtained 

 by the action of chemical substances, which cause the contraction of 

 the protoplasm, by the tendency of the little ovule to acquire a 

 rounded form under the influence of those reagents. — Comptes 

 Rendm, December 20, 1869, tome Ixix. pp. 1320-1324. 



On some Mammalia from Eastern Thibet. 

 By M. A. Milne-Edwakds. 



Two monkeys inhabit the coldest and least accessible forests of 

 eastern Thibet. One is a Macacus, allied to M. speciosus and M. 

 tcheliensis, in which the tail is very short. Its coat is of a dark 

 greyish brown ; the hairs, which are very long and thick, present 

 no diff'erently coloured bands ; the lower parts of the body are of a 

 much lighter grey, and the face and hands are flesh-coloured. The 

 species is named M. thibetanus. 



The second species is a Hemnopitliecus, named S. roxeUana by the 



