USE OF THE MICROSCOPE IN ZOOLOGY. 



43 



Animalculse (Fig. 17). Other interesting forms of the 

 Vorticellina family you are sure to meet with, such as 

 Epistylis and Carchesium. In individuals of the former 

 genus, the 

 flowers droop 

 from a stem 

 in a tree-like 

 form, the foot- 

 stalks having 

 no retractile 

 power; in Car- 

 chesium the 

 bells orflowers 

 spring from a 

 single non-re- 

 tractile trunk, 

 but the stems, 

 which are very 

 numerous, are 

 all retractile. 

 On the stems 

 and leaves of various aquatic plants you will see 

 other interesting little creatures of the same family 

 each inhabiting a tube. A great number of species 



have been described ; 

 but you will recognise 

 the general form when I 

 tell you that the animal- 

 cule is like a Stentor. It 

 is very curious to witness 

 this animal protrude itself 

 out of its case. Within 

 its case, which is often 

 very transparent, and 

 which perhaps would es- 

 Fi g . ig.-carchesium. cape your detection were 



Fig. 17. Vorticella. 



