378 Mr. J. Scullj on Mammals from Afghanistan. 



condition is secondary may be asserted most decidedly, as the 

 Spatangida are palseontologically the youngest forms. 



A remarkable organ is the " ovoid gland," the structure 

 formerly designated the heart. So far as one is justified in 

 judging from the extant results, we may regard it as an organ 

 in which materials no longer available for the body are depo- 

 sited. Blood-lacunee open at the ends into it or surround it, 

 as in the Echinida. No efferent duct has yet been found in 

 any group. 



The origin of the sexual products is of especial interest ; 

 they consist of primordial germ-cells ( Urheimzellen) , as I have 

 proposed to name these cells. They lie in the dorsal wall in 

 an annular genital tube, on which five sacciform diverticula 

 are formed, into which the primordial germ-cells pass. These 

 diverticula form the first foundations of the sexual tubes. 

 From the primordial germ-cells the ovicells are produced by 

 growth &c. ; and by division &c. the sperm- cells, as well as 

 the whole of the epithelium which afterwards lines the sexual 

 organs. 



In mature animals these sexual tubes are atrophied. How 

 far a similar origin of the sexual products from such primor- 

 dial germ-cells prevails in all Echinodermata I shall show 

 immediately in another place (Zeitschr. fiir wiss. Zool. 

 Bd. xlvi.Heftl). 



LI. — On tlie Mammals collected hy Captain C. E. Yate^ 

 C.S.I., of the Afghan Boundary Commission. By J. 

 Scully *. 



Me. Wood-Mason has asked me to contribute a paper on the 

 collection of mammals and birds made by Captain C. E. 

 Yate in Northern Afghanistan, and presented by that officer 

 to the Indian Museum ; the following notes are the result. 

 The collection, I understand, was made after the departure of 

 the naturalist of the Commission, so it may possibly include 

 some forms not secured by him, and doubtless additional 

 localities will now be made known for many of the species 

 previously obtained. 



* From a separate impression from the ' Journal of the Asiatic Society 

 of Bengal, part ii. 1887, communicated by the Author. [The section 

 relating to the Birds has not been reprinted, as it consists, almost exclu- 

 sively, of a list of the species observed.] 



