54 



MANUAL OF ZOOLOGY 



SECT. 



Dendrosoma (Fig. 20, p), one of the Tentaculifera : it has 

 a creeping stem from which branches spring upwards, 

 each terminating in a zooid with suctorial tentacles ; and 



FIG 



. 22. Vorticella. A, B, living specimens in different positions; C, optical 

 section; D 1 , D 2 , diagrams illustrating coiling of stalk; E 1 , E 2 , two stages in 

 binary fission; E 3 , free zooid; F 1 , F 2 , division into mega- and microzooids; 

 G 1 , G 2 , conjugation; H 1 , multiple fission of encysted form; H 2 , H 3 , develop- 

 ment of spores; ax.f, axial fibre; cort, cortex; cu, cuticle; c. -vac, contractile 

 vacuole ; d, disc ; gull, gullet; m, microzooid; wM, mouth; MM, meganucleus; 

 per, peristome. (From Parker's Biology, partly after Saville Kent.) 



