24 CALIFORNIA ACADEMY OF SCIENCES. 



4. In one or more of the separating individuals, the 

 process of sporulation — forming of a sporogonium — may 

 be more advanced than in any of the other parts, while 

 all are yet connected together. 



5. The formation of a new perfect nucleus as in fig. 

 41, probably depends upon the accidental accumulation 

 of sufficient nuclear matter in one place. 



LARGER CYSTS. 



In figs. 43 and 44 I have figured two very large and 

 unusual forms. One of these is a very young form, 

 irregular in outline, with very small cytospheres and no 

 nuclei. The other is undoubtedly a sporogonium stage, 

 with a very thick cytotheca, if we here have to deal with 

 a formation of a different kind of cyst or with abnormal 

 forms of the common cyst is undecided. 



I found only few of these forms and onl}^ in the Ecli- 

 pidrilus host. 



AFFINITIES. 



The characters of Spermatobium appears to be inter- 

 mediate between Klossia and Monocystis, and I think 

 demonstates that the gregarines cannot properly be sys- 

 tematically divided accordingly as their habitat as intra- 

 cellular and coelomic. 



In Spermatobium the young individual inhabits the 

 spermatogonium or mother cell, just as Monocystis, and 

 the adult dwells free in the fluid surrounding the sperm 

 cells. As in Monocystis, Spermatobium develops shuttle 

 and pseudonavicella spores, the resemblance between the 

 spores in the two genera being very great. 



But the formation of the sporogonium, the sporoblasts 

 and the spores resemble much more that of Klossia and 

 Monocystis. While in Monocystis the cyst contains a few, 

 generally two, sporogonia of unequal and irregular size, 



