550 Dobell, Some Kemarks upon the „Autogamy" of Bodo lacertae (Grassi). 



the „chromidia" appeared massed together (e), forming the new 

 „sexual nucleus" — which, when fully formed appeared beside the 

 „somatic nucleus", thus giving rise to a binucleate cyst (/'), I fur- 

 ther found stages — though these were few — in which the 

 „sexual nucleus" was dividing {g), and more frequently cysts in 

 which the „sexual nucleus" appeared to have given rise to two 

 „daughter nuclei" {h). Quite a number of cysts presented appearances 

 which could be interpreted as subsequent divisions of these nuclei. 

 For example, in / one nucleus alone is apparently in division, 

 whilst in k both „nuclei" have divided, forming the first pair of 

 „reduction nuclei". In / a somewhat similar stage show is. After 



Fi.e;. 1. 



searching for them, I was able to find cysts (/«) which showed the 

 formation of the „second reduction nuclei". In all these stages 

 the somatic nucleus is still present. It usually has an annular 

 appearance, with a large peripheral karyosome. It is interesting 

 to compare this with the „somatic nucleus" in Bodo. During these 

 stages Prowazek describes this as the . . . „alten Kern, der blass 

 und chrornatinarm ist und nur ein weitmaschiges achromatisches 

 Gerüstwerk, dem seitlich der oft zerfallene Innenkörper anliegt, 

 besitzt ..." And further he i-emarks. „Der alte Kern blasst stetig 

 ab und das Chromatin verklumpt öfters in Brockenform an seiner 

 Peripherie." In the cyst depicted in n we apparently see the 

 „autogamy" of the „reduced nuclei", while the four little „reduction 



