Fig. 10.— a group of Vorticellae ; x 220 (c. h. h.) 



Figs. I, II, and III show the animal in various positions. lY is a much smaller 

 specimen drawn to the same scale. V shows a specimen made to contract by 

 action of alcohol. TI is detached from its stalk, and swimming away freely, 

 disc forwards. YII, VIII, IX show three stages of fission. X, XI, and Xn 

 show the separated individual swimming by means of the aboral circle of cilia : 

 XI is slightly contracted, XII strongly contracted after the cover-glass has 

 been tapped. 



A, Food vacuole discharging contents at anus. C, Peristomial cilia. OF, 

 contractile fibre of stalt. D, disc. D', disc retracted. PV, food vacuole. 

 FH, pharynx. PV, pulsating vacuole. P, peristome. M, myophan striation. 

 US", nucleus. V, vestibule. 



