l62 



PROTOZOA 



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

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

 on special parts of these. Thus Rhyncheta is only found on th< 

 couplers of the thoracic limbs of Cyclops, and Choanophrya 01 

 the ventral surface of its head and the adjoining appendages. 



,tr 



J:r 





Fig. 62. Choanophrya infundibulifera. A, adult ; B-D, tentacles in action in various 

 stages ; E, tentacle at rest ; F, young, just settled down, a, a, 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. ) 



We owe our knowledge of this group to the classical works 

 of Ehrenberg, Claparede and Lachmann, Stein, E. Hertwig, and 

 Biitschli. Plate has shed much light on Dendrocometes, and 

 Hickson has studied its conjugation. Ischikawa l has utilised 

 modern histological methods for the cytological study of Ephelota 

 oiitschliana. Bene Sand has written a useful, but unequal, and 

 not always trustworthy monograph of the Order, 2 containing an 

 elaborate bibliography. 



1 In Journ. Coll. Sc. Japan, x. 1896. 



2 ]tude monographique sur Ic groupe des Tentaculiferes, Ann. Soc. Beige Micr. 

 xxiv.-xxvi. 1901. 



1 



