80 



BIOLOGY OF THE PROTOZOA 



endobasal body, there are other types {e. g., Myxoholus jjfeifferi, 

 one of the Myxosporidia) in which the centriole emerges from an 

 enveloping phistin-hke matrix, which, hke a nucleolus, then degen- 

 erates and disappears. 



An interesting variation of this type of endobasal bodies is illus- 

 trated by Amosba xespertiliu as described by Doflein. Here the 

 endosome is composed of chromatin, plastin and kinetic elements 

 and all parts of the spindle are made up solely from these endosomal 

 substances, while the outer nucleus appears to be passively divided 



Fig. 37. — Bodo lacerfw Grassi. Early stages of division of the basal bodies, (bb) ; 

 blopharoplast ring (bl); nucleus and parabasal body (p). (After Belar.) 



(Fig. 39). In contrast with, this may be cited the observation of 

 Enriques (1913) who found complete spindles without trace of 

 chromatin. 



Centrioles, finally, may be present without other covering or 

 enveloping substances as in the case of Paramoeba chcefognatha 

 (according to Janicki, 1912), or in Centropy:cis aculeata according 

 to Schaudinn, 1903). In the former a centrodesmose is formed 

 during division stages; in the latter no centrodesmose occurs but 

 the centrioles at the poles of the mitotic spindle, as in a metazoon 



