ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 279 



substance. On neither side does it share in the development of the 

 thyroid gland. 



Poly-embryony of Tatusea hybrida.* — Miguel Fernandez u^ds 

 that in this armadillo there is, to begin with, a single blastoderm with 

 inversion of the germinal layers. On the ectoderniic vesicle, at first 

 uniformly thick, an endothelium-like pole differentiates towards the 

 trophoderm and towards the diplotrophoblast, with an annular zone of 

 thick epithelium between. From the latter, and from the thin portions 

 of the vesicle that are turned trophoderm- wards, blind diverticula grow 

 out which become the primordia of embryos, either directly or after 

 division. The rest of the vesicle becomes the common amniotic cavity. 

 The endoderm of the various single embryos differentiates in loco from 

 the single primitive endoderm sac, and in response to ectodermic 

 stimulus. 



Umbilical Vesicle of a very young Human Embryo. f — A. Debeyre 

 previously described the umbilical vesicle of a human embryo which 

 measured scarcely 0*9 mm. He now describes a second stage from an 

 embryo of 4 • 5 mm. The general resiilt is that the vesicle in the first 

 stage of its development presents a structure comparable to that of the 

 intestinal endoderm, and in its second stage the features of a secreting 

 surface. 



Development of Gland of Third Eyelid in Ox. J — C. Mobilio traces 

 the development of this gland from its origin as an ectodermic bud, 

 arising from the proliferation of the deep layer of the embryonic con- 

 junctiva. Several other buds (1-4) may be associated with the original 

 bud, but the latter is most important. The gradual changes from solid 

 spherules to more or less complete tubes are described. 



Albino Tadpoles of Toad.§ — Jaromir AVenig found sixteen larvge, 

 almost certainly of Bufo vulgaris, in Ton-earth pools with turbid water 

 in north-east Bohemia. There was an almost entire absence of pigment 

 in the integument, and it was greatly reduced in the eyes. There were 

 numerous normal tadpoles living along with the albinos. In the internal 

 organs, e.g. about the brain, there were scattered chromatophores. The 

 author discusses the possible factors in inducing the albinism, such as 

 lack of food and the composition of the water, but he concludes that 

 the peculiarity must be referred to a germinal pathological variation. 



Degeneration of Uterine Embryos of Salamandra maculosa. 1| 

 Laure Kaufman describes degenerative changes which often occur. 

 These may be due to non-fertilization, inadequate nutrition, and me- 

 chanical pressure. The larvae depend on their own yolk material, and 

 get nothing from the uterine wall. Degenerative changes are described 



* Resumes des Communications, 9e Internat. Congres Zool., 1913, p. 14. 

 t C.R. Soc. Biol. Paris, Ixxiv. (1913) pp. 670-2. 

 X Anat. Anzeig., xliii. (1913) pp. 289-313 (12 figs.). 

 § Anat. Anzeig., xliii. (1913) pp. 113-55 (13 figs.). 

 ;i Bull. Acad. Sci. Cracovie, 1913, pp. 24-31 I'l pL). 



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