Fig. 49. — Stages in the keimbahn of copepods. A-G. Cyclops fuscus 

 var. distinctus. H. Diaptomus coeruleus. I. Cyclops viridis. 

 A. Ectosomes at end of first cleavage spindle. B. Two-cell stage ; 

 ectosomes dissolving. C. Old and newly formed ectosomes at end 

 of one of second cleavage spindles. D. Eight-cell stage ; ectosomes 

 dissolving in stem-cell. E. Sixteen- to twenty-eight-cell stage. 

 S = cell with, E = cell without, granules. F. One hundred and 

 twelve-cell stage with two primordial germ cells (u) and three en- 

 toderm cells (E). G. Two hundred and forty-cell stage, u = pri- 

 mordial germ cells. H. Appearance of ectosomes before cleavage 

 spindle forms. I. Increased production of ectosomes due to car- 

 bonic acid gas. (From Amma, 1911.) (166) 



