DEVELOPMENT OF SPERMATOBIUM. I9 



structures but only accumulations of organic secretions of 

 different states of liquidness, appears to explain the nu- 

 cleolar structure of Spermatobium. 



SPORULATION. 



The sporulation is undoubtedly the chief object of the 

 adult Spermatobium, and it depends chiefly on this process 

 for the maintenance of the species. In the various phases 

 of sporulation we have, in fact, the larger part of the life 

 history of this protozoa. Sporulation, or the forming of 

 spores, comprises again various stages of development. 

 These are : 



A. Preparatory stages and amitosis. 



1. Diffusion or budding of macronucleus. 



2. Formation of numerous micronuclei. 

 B- Formation of spores, 



3. Attraction by the micronuclei of cytospheres, 

 forming sporoblasts. 



4. Divisions of micronuclei by caryokinesis. 



5. Transformation of each sporoblast into a shut- 

 tle spore. 



6. To this may be probably added another stage, 

 the formation of sickle germs in the shuttle 

 spore. This stage I have not observed, and 

 its existence can only be inferred from what 

 takes place in other protozoa. 



When the adult Spermatobium has begun the process of 

 sporulation it may be more properly called a sporogonium 

 or rather macrosporogonium, as at a later stage this ma- 

 crosporogonium divides into numerous microsporogonia. 

 The smaller agglomerations of cytospheres and micronu- 

 clei may again be termed sporoblasts. 



Strictly speaking, the sporulation begins with forma- 

 tion of sporoblasts. After the micronuclei have con- 

 tracted their plasma filaments and attained their proper 



