i6: 



PROTOZOA 



some of them indifferent to their base ; others are only found on 

 Algae, or again only epizoic on special Metazoan hosts, or even 

 on special parts of these. Thus Ilhynchcta is only found on the 

 couplers of the thoracic limbs of Cyclops, and Choanophrya on 

 the ventral surface of its head and the adjoining appendages. 



Fig. 62. — Chomwphn/a infundibulifera. A, adult ; B-D, tentacles in action in various 

 stages ; E, tentacle at rest ; F, young, just settled down. «, «, a. Tentacles in various 

 stages of activity ; c, central cavity ; c. v, contractile vacuole ; em, ciliated embryo 

 showing contractile vacuole and nucleus ; /, spiral ridge ; m, muscular wall of 

 funnel ; n, nucleus ; tr, opening of funnel. (A-D, F, modified after Zenker ; E, 

 original. ) 



AVe owe our knowledge of this group to the classical works 

 o{' Ehrenberg, Claparede and Lachmann, Stein, E. Hertwig, and 

 lUitschli. Plate has shed much light on Dcndrocometes, and 

 Hickson has studied its conjugation. Ischikawa ^ has utilised 

 modern histological methods for the cytological study of Ephelota 

 hiitschliana. Eene Sand has written a useful, but unequal, and 

 not always trustworthy monograph of the Order,^ containing an 

 elaborate bibliography. 



' In Journ. Coll. Sc. Japan, x. 1S96. 



- J^tude monographique sur Ic groupc des Tcntaculiftres, Ann. Soc. Behjc Micr. 

 xxiv.-xxvi. 1901. 



