228 



BIOLOGY OF THE PROTOZOA 



nuclei of the so-called buds (Fig. 63). In Councilmania lafleuri, 

 Kofoid and Swezy (1921) which is considered an aberrant form of 

 Endavioeha coli by some authorites, the phenomenon of exogenous 

 budding is quite different from so-called budding in the amoeba? 

 mentioned above. Here according to Kofoid and Swezy, the nucleus 

 divides three or more times to form from eight to sixteen nuclei which, 

 enclosed in buds of cytoplasm are successively pinched off from the 

 surface of the amoeba (Fig. 110). 



In Acantlwcysiis aculeata according to Schaudinn (1896) and in 

 Wagnerella borealis according to Zuelzer (1909) the nucleus of the 

 cell divides one or more times by simple constriction and without 

 the formality of mitosis or participation of central granule. The 

 minute nuclei thus formed wander to the periphery of the cell where 



^[j i Tf^"^ ^/^f M.<M i'^4 - 





Fig. 109. — Exogenous buds of Noctiluca miliaris. (After Robin.) 



they are pinched off in minute cells. In Acanthocystis these buds 

 form minute ama'b?e which after four or five days of activity settle 

 down and metamorphose into young Heliozoa. The buds have no 

 central granule but during metamorphosis a kinetic element emerges 

 from the nucleus and this becomes the central granule of the adult 

 Acanthocystis (Fig. 100, p. 214). In Wagnerella borealis, according 

 to Zuelzer, the buds which are formed in a similar manner are 

 flagellated, but her description in other respects follows that of 

 Schaudinn. 



In Infusoria, particularly in Suctoria, exogenous budding is not 

 uncommon. In Ciliata it is comparati\'ely rare and limited appar- 

 ently to the Spirochonidse. In Spirorhona gemmipara according to 

 Hertwig a swelling appears at one side of the base of the peculiar 



