IIL,.2c. 132 Ilia. 6. 



2c. Complete development or development daring special periods 

 (e.g. early, late, etc.) of cell-constituents and special sub- 

 stances. 



Early development. 



3. Implantation, placentation and development of fetal membranes. 



M. Implantation of blastocysts in Rhodentia. 



J. KRAHELSKA 

 M. Development, structure and functions of trophoblast. Illb. 3. 



Homo, Rattus and Lepus. B. N. KROPP 



4. Ovogenesis, spermatogenesis, structure of egg and sperm, 

 maturation, oviposition, fertilization (activation, parthen- 

 ogenesis). 



E. Nature of polar plasms. Limnaea stagnalis (Gastro~ Illb. 4. 



poda). Chr. P. RAVEN 



H. Protoplasmic movements after fertilization of Ascidia 



aspersa. G. VANDEBROEK 



J. A continuation of the study of the origin of the diploid IIIc. 2. 



and other chromosome numbers in parthenogenetically 

 developed frog embryos. Rana pipiens and R. palustris. 



Ch. L. PARMENTER 

 M. The parthenogenetic development of unfertilized ova 

 induced by chemical stimulation. Albino rat. 



S. PESONEN 



5. Cleavage. 



D. Determination der Furchung und Sonderung der Ilia. 2a. 

 Organanlagen bei Daphnia (Crustacea). 



F. KAUDEWITZ 



6. Gastrulation. 



H. Morphogenetic movements during the gastrulation of 

 Ascidia aspersa and Styela partita (Ascidians). 



G. VANDEBROEK 



H. The mechanics of gastrulation in Ascidia aspersa and 

 Styela partita. G. VANDEBROEK 



I. Mechanism of gastrulation in teleost eggs. The nature Illb. 6. 



of the surface gel layer of the egg and its possible role 

 in the cell movements (particularly epiboly) charac- 

 teristic of teleost gastrulation. Extensive utilization of 

 the methods of marking, wounding, transplantation. 

 Fundulus heteroclitus (Osteichthyes) . 



J. P. TRINKAUS 



