518 



There is a very slight indication of a division into ectoplasm and endo- 

 plasm and the entire cell has a well-defined reticular appearance, which 

 upon closer examination is undoubtedly due to the optical section of 

 the walls of alveoli (fig. 4 and fig. 5). The most significant feature 

 about the adult structure, and indeed throughout the entire life-hi- 

 story of the parasite, is the fact that there is no well-defined nucleus. 



Fig. 5. Adult individuals found in the lymph. Camera lucida X 2000. 



The body of the cell is well filled with distinctly-staining granules, 

 and for a long time the animals were overlooked because of their 

 striking resemblance to the nuclei of muscle cells (fig. 4), Apart 

 from the developmental phases which show that they cannot be muscle- 

 cell nuclei, these cells stain more intensely than do the tissue nuclei, 



A 



B 



Fig. 6. Spore-forming individuals from the lymph-spaces. A Groups of deeply- 

 staining granules aggregating to form spores; B Later stage. Camera lucidaX 2000. 



and possess no karyosomes or nucleoli, while their position is further 

 evidence of their independent organization. 



So far as I am aware the distributed nucleus, although described 

 n some rhizopods, flagellates, and ciliates, has never been recorded 

 for a Sporozoon. In the present case I have observed no concentration 

 of the granules of chromatin as in the flagellate Tetramitus 2 , nor any 



2 cf. Calkins, Annals N. Y. Acad. Sc. 1898. 



