Vorticelltna.} infusorial animalcules. 541 



At the large, lateral, somewhat anterior mouth, to and from which 

 the alimentary canal is seen running, the discharge of matter also 

 takes ijlaee. They arc hermaphrodite ; self-division, and free sepa- 

 ration of the body from the stalk, have been observed. It is very 

 remarkable that below its proper bodies, more especially in the axillas 

 of the branches, thci'c are seen large single bodies, and even larger egg- 

 shaped ones, having hairs at their point, and only a small round, but 

 not vibratile opening. The latter ones are most probably parasitical 

 bodies, the others are not. This genus is not figured by Ehrenberg. 



Opercularia articiikta ( V. Opermlaria, M.) — Occurs as a little 

 shrub, l-6th to 1 -4th high, white and dichotomous. This animalcule 

 readily takes in cannine and indigo ; and Ehrenberg states, he saw as 

 many as forty-four stomach-cells filled, resembling a girdle in the 

 middle of the body. The stalk is verj' delicately striated in a longi- 

 tudinal direction, and shews, at its divarications, a transverse line, or 

 joint. Found upon Dyticus marginatus. Size l-430th. 



Genus Zoothamniuji. The doiible-shiped little bell Animalcules 

 comprehend Vorticellina with a flexible spiral pedicle, having an 

 internal muscle, and becoming branched, from imperfect spontaneous 

 di%dsion. The stalked corpuscles are of different shapes, and have a 

 simjjle, lateral, oral opening. In one species, a wreath of cilia placed 

 around the frontal region, constitutes the locomotive apparatus; 

 and a special muscle or fibre rims along the branches and stem. 

 Artificial means are able to demonstrate numerous roimd stomach- 

 cells. No reproductive organs have been detected ; but simple and 

 compound self-division have been observed. 



Z. arbuscula ( Vorticella racemosa, M. and Duj.) — Has the branches 

 of the little tree in racemes or umbels ; the corpuscles being white, 

 and the pedicle very thick. (See fig. 247, which is more highly 

 magnified than 248). These beautiful little trees resemble plumes 

 of feathers, at once distinguishing themselves by their strong branches, 

 but haWng the characters of Carchesium and Opercularia, as respects 

 the presence of globular bodies in the asiUae of the branches. When 

 fuU grown, all the animalcules free themselves from the pedicle, 

 which afterwards \vithers and disappears. Found uponCeratophyllum, 

 stalks of the water lily and of other aquatic plants ; it is visible to the 

 naked ejc. It contracts itself on ever}- alarm, by the muscle which i uus 



