Megalotrochaea.] THE INFUSORIA. 341 



developed within the vesicle of the nucleus or yolk, and 

 becomes visible when this latter is consumed; a turbid 

 central spot then appears, which becomes the oesophagal 

 bulb and teeth ; a blackish granular oval body is also seen 

 posteriorly, the eyes gradually become red, and a motion 

 of the cilii is visible : after some hours the whole foetus, 

 which is folded up, turns itself round, the shell bursts, 

 and the young animalcule creeps out ; it then fixes itself be- 

 tween the older ones, but in a little time the young creature 

 detaches itself and swims about as a rolling sphere, but, at 

 the expiration of a certain period, attaches itself to some 

 firm body." Figures 374 to 376 represent different speci- 

 mens; figure 377 is merely the teeth and jaws separate. 

 Found upon water plants. Size of single animalcule 

 l-36th; of the spheres I-6th. 



