'24 Art. R.— I. Ikedii finfl Y. Oz.aki : 



^nuclear raiiltiplication advances, the entire cyst grows larger and 

 larger until it measures about 85/^ in diameter. The inclosed 

 /' Fig. 21. cynthytial mass lecomes at first irregular- 



=.^.,^ shaped, and later complicately lobed and reti- 



• .;, culated, recalling the plasmodial body of a 



tS>.. * ; ; certain mycetozoan. 



'K^N J ; ^'/^ Fig. 21 represents a cyst grown to maxi- 



mum size, in which the poly nucleate and 



Cyst of the second tyiie. 



'Technique the same ns in rcticulatcd appcarauco of the cyst coutcnts is 



'the preceding figure. , • , i , -, - -, . ,- -^ -, . 



shown m the most advanced state. In this 

 case of encystment too, we have not been able to ascertain the 

 fate of the cyst. ; " 



Summary. 



1. Boreria labialis mainly differs from B. suhcylindrica Stevens 

 in lacking the cytoplasmic lenticular mass in the aboral region and 

 in possessing a lip-like appendage on the peristomal disc. From 

 B: suhcylindrica var. ncapolitana Stevens it further differs in the 

 rounded, instead of the pointed shape of the aboral end, and in the 

 larger extension of the oral ciliary spire. 



2. The conjugation is isogamie. Two individuals come into 

 attachment with their aboral ends. 



3. Tlic micronucleus in the ordinary fission and also the 

 synkarion form four distinct chromosomes in the same way. During 

 the conjugation, the micronucleus divides in two different ways; 

 i.e., its first division is amitotic, while its second and third divisions 

 are mitotic and give rise to numerous chromatin threads instead 

 of four chromosomes. The third micronuclear division seems to 

 be a reducing division. 



4. The conjugant meganucleus persists as such in the ex- 

 con jugant. This, persistent nucleus absorbs three quarter-portions 



