26 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Note on the History of Merogony.* — Prof. A. Giard points out 

 that the first to discover the possibility of merogony was J. Rostafinski,| 

 who experimented on the ovum of Funis. A useful summary of his 

 paper is given. The method used was bruising and cutting. Prof. 

 Giard also recalls Balbiani's experiments on merotomy of Infusorians, 

 but concludes that merogony was first demonstrated in plants by Kosta- 

 finski (1877) and in animals b}* Boveri (1885). 



Influence of Spermotoxin on the Fertilising Power of Spermato- 

 zoa.! — Mile. C. de Leslie injected male white mice with spermotoxic 

 serum furnished by the guinea-pig, and found that sterility resulted, 

 lasting for 16-20 days. There was no effect on the sexual appetite or 

 on the spermatogenetic function, but the spermatozoa had lost their 

 fertilising power. 



Germ-layers of Vertebrates.§ — Prof. Oscar Hertwig returns to the 

 discussion of some contested points in regard to this subject. The first 

 of these has reference to the question as to what represents the gastrula 

 in the development of the three highest vertebrate classes. The author 

 believes that, to decide this point, it is necessary to distinguish two 

 phases in gastrulation in the Anamnia. The first phase, that in which 

 the layer lining the future intestine is formed, cannot be said to be 

 •definitely represented in Amniota ; but the second, that in which the 

 mesoblast and notochord originate from cells in the vicinity of the 

 blastopore lip, is distinctly shown, and may be emphasised by the ap- 

 pearance of small invaginations, such as those of the embryonic shield 

 in certain reptiles. 



The second disputed question is the part played by the blastopore 

 in the formation of the Vertebrate body. Hertwig believes that the 

 lips of the blastopore fuse together in front along the middle line, and 

 at the same time go on growing backwards so long as the body continues 

 to increase in length. He thus holds that the blastopore is an important 

 factor in the formation of the dorsal region of the embryo ; while some 

 other embryologists believe that the increase in length of the embryo 

 is due to a special zone of growth in front of the blastopore. Hertwig 

 flnds confirmation of his own view in the malformation known as spina 

 bifida, which is most readily explained as due to want of fusion of the 

 lips of the blastopore. 



Origin of Cerebral Hemispheres.[| — Prof. F. K. Studnicka main- 

 tains that the cerebral hemispheres have from the first a paired origin, 

 which is by no means the general conclusion. The cerebral hemi- 

 spheres arise from the upper portions of the lateral walls of the primi- 

 tive first vesicle, and are as truly paired, as the eyes are. At the same 

 time it is admitted that the median anterior portion of the first vesicle 

 may grow forward into an " epencephalon." 



Development of Tongue in Man.^f — J. Aug. Hammar finds that the 

 tuberculum impar is not the rudiment of the tip and body of the tongue, 



* Comptes Rendus Soc. Biol., Oct. 10, 1901, 3 pp. 

 t Osobne odhicie z Kozpraw Akad. Umiejet, 1877. 

 X Comptes Rendus, exxxiii. (1901) pp. 514-6. 

 § SB. Akad. Wiss. Berlin, xxiv. (1901) pp. 52S-33. 



I! SB. bohmisch. Ges. Wiss., 1901, 33 pp. mid 11 figs. See Zool. Centralbl., viii. 

 {1901) pp. 776-7. If Annt. Anzeig., xix. (1901) pp. 570-5. 



