54 



MANUAL OF ZOOLOGY 



SECT. 



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

 a creeping stem from which branches spring upwards, 

 each terminating in a zooid with suctorial tentacles j and 



'dkk> 



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

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

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

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

 ment of spores; ax. f, axial fibre; cart, cortex; cm, cuticle; c. vac, contractile 

 vacuole; d, disc; gull, gullet; m, microzooid ; mth, mouth; nu , meganucleus; 

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



