ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 341 



Reproductive System of Female Mole.* — F. Wood-Jones calls 

 attention to the remarkable state of affairs in the female mole which 

 passes from an apparently male arrangement of external genitalia into 

 one that is obviously female, and develops in post-natal stages an en- 

 tirely new genital orifice. Although the peculiarities of the female 

 reproductive system appear at first sight to be extremely anomalous, 

 they are seen to have, for the most part, some foreshadowing in the 

 normal processes of development of other mammals. Everything that is 

 unusual in the female reproductive system is initiated in the early stages 

 of embryonic development when, between the 9 mm. and 18 mm. stages, 

 the labio-scrotal folds begin to grow towards the middle line over the 

 closed urethra in the base of the genital tubercle. In the method of 

 development of the external genitalia the male mole falls into liue with 

 some other members of the Insectivora, the Rodentia, Ungulata, and 

 some other orders. The female alone is anomalous, and that in follow- 

 ing from the first a male type of formation of the external genitalia. 

 This state of affairs seems to occur again in Hyaena crocuta. 



There is a shifting of the site of opening of the Mullerian ducts ; 

 and they end in solid epithelial prolongations. But both these phases 

 occur in the normal development of other animals, and both are stages 

 in the normal formation of the female genital system in Homo. The 

 imperforate vagina is a normal stage in the female human embryo, and 

 this solid vagina becomes patent in very much the same way as does that 

 of the mole — by desquamation of its central cells. What is exceptional 

 in the mole is that the opening up of the solid vagina is so long de- 

 layed. Again, it is not without parallel that a vagina once formed 

 should become occluded again, as happens in the mole, and be re-opened 

 when functional activity next demands a passage. These phases have 

 been established by Hill with regard to the median vagina of Perameles. 



Seasonal Changes in Testes and Plumage in Wild Duck.f — C. G. 



Seligmann and S. G. Shattock have enquired into the reality of a corre- 

 lation between seasonal changes in the testes and the " eclipse " plumage 

 of the mallard. As in many other birds, the testes of the mallard 

 undergo a series of seasonal changes, and are spermatogenic only during 

 the winter months and early spring. But the two periods of activity 

 and non-activity do not coincide with the two seasonal changes in the 

 plumage. 



The normal passage of the bird from full winter (breeding) plumage 

 to its dusky summer (eclipse) plumage is, however, delayed if castration 

 is effected during the months whilst the gonads are assuming or have 

 attained activity. One bird which was castrated in the winter, and in 

 which the advent of the succeeding eclipse was delayed the following 

 summer, was kept until the summer of the next year. The second 

 eclipse occurred at the normal period, but nodules of regenerated 

 testicular tissue were found. It is a remarkable fact that the grafts 

 were fully spermatogenic in the month of September, an occurrence 

 altogether abnormal in the testicle of the entire bird. The delay above 



* Proc. Zool. Soc, 1914, pp. 191-216 (3 pis. and 13 figs.). 

 t Proc. Zool. Soc, 1914, pp. 23-43. 



