184 GERM-CETJ. CYCLE IN ANIMALS 



A similar interpretation is given by Haecker for the 

 cytoplasmic inclusion ("Spermakern") found by 



Boveri (1890) in 

 Tiara. Similarly 

 the ''Kleinkern" 

 which Chun (1891) 

 discovered in the 

 egg cells of Ste- 

 phanophyes su- 

 perba, and the 

 bodies described 

 by Hertwig (1878) 

 near the matura- 

 tion spindles of 

 Mytilus and Sa- 

 gitta, resemble 

 very closely the 

 metanucleolus of 

 ^quorea. 



Furthermore, 

 the metanucleolus 

 is considered by 

 Haecker homolo- 

 gous to the "Par- 

 acopulationszelle 

 described by Weis- 

 mann and Ischi- 

 kawa in the winter 

 eggs of certain 

 Daphnid^, and in both cases it is considered prob- 

 able that these peculiar bodies are restricted to the 

 *'Keimbahnzellen" of the embryo. 



Fig. 55. — A-D. Stages in formation of 

 blastula of jEquorea forskalea showing seg- 

 regation of metanucleolus. {From Haecker, 

 1892.) E. Oocyte of the cat containing 

 the "corps enigmatique" (c.e). {From 

 Vander Stricht, 1911.) 



