VI ANIMALS AND PLANTS 191 



fought over it, Volvox is now finally surrendered to 

 the Botanists. 



Thus there is really no reason why Heteromita 

 may not be a plant ; and this conclusion would be 

 very satisfactory, if it were not equally easy to 

 show that there is really no reason why it should 

 not be an animal. For there are numerous 

 organisms presenting the closest resemblance to 

 Heteromita, and, like it, grouped under the general 

 name of " Monads," which, nevertheless, can be 

 observed to take in solid nutriment, and which, 

 therefore, have a virtual, if not an actual, mouth 

 and digestive cavity, and thus come under Cuvier's 

 definition of an animal. Numerous forms of such 

 animals have been described by Ehrenberg, 

 Dujardin, H. James Clark, and other writers on 

 the Infusoria. Indeed, in another infusion 

 of hay in which my Heteromita lens occurred, 

 there were innumerable such infusorial animalcules 

 belonging to the well-known species Colpoda 

 cueullus)- 



Full-sized specimens of this animalcule attain a 

 length of between -g-J-g- or -j-J-g- of an inch, so that it 

 may have ten times the length and a thousand 

 times the mass of a Heteromita. In shape, it is 

 not altogether unlike Heteromita. The small end, 

 however, is not produced into one long cilium, 

 but the general surface of the body is covered with 



1 Excellently described by Stein, almost all of whose state, 

 mcnts I have verified. 



