THE AMERICAN NATURALIST. [Vol. XXXVIII. 



the velar fold they are later carried outwards from the wall of 

 the embryo and ultimately hang down from the under side of the 



Between the two extremes in development mentioned, the 

 cells composing these bodies increase in size, in number by addi- 

 tion, and undergo a period of active excretion. Early in this 

 period the nuclei divide amitotically, and the cells become poly- 

 nucleated. The nuclei are granular, very irregular in outline, 

 and each one has at least one nucleolus surrounded by a clear 

 area. In addition the cells are characterized by their highly 

 vacuolated condition (Fig. i). 



In sections through these nuclei, before and after amitosis. 



chromatin is arranged in an irregular network (Fig. 2 

 1^. C ). The nucleolus (///) has a different staining reaction, 



IS probably a typical plasmosome. The halo surrounding it, 

 cad of being circular or oval in outline, as it appears to be 

 ^^holc mounts and in optical sections, is highly irregular, its 

 me projecting in finely attenuated processes into the body of 



