INFUSORIA 449 



ciliary current. They did not attack any other part, and 

 *fter having continued their murderous occupation about 

 ten minutes, they one by one departed. The ciliary mo- 

 tion of the Euchlanis ceased immediately after it was first 

 attacked, and I suppose it was soon killed, for it did not 

 increase in size in the least afterward. When the Colepes 

 left it, a great portion, perhaps a third, of the excluded 

 parts was devoured. 



As soon as the depredators were gone, or even before, 

 others more diminutive, but more numerous, were ready 

 to take their place. The drop of water under review had 

 been found amazingly full of a small Monas, perfectly 

 transparent, of an oval form, with some granules visible 

 in the interior. They were about srJWth of an inch in 

 length. They filled the whole field, gliding about very 

 nimbly, but so close as but just to allow space for motion, 

 and that in several strata. By the morning these were 

 collected in masses, which, to the naked eye, looked like 

 little undefined white clouds, but which under the micro- 

 scope showed the Monads in incalculable multitudes, but 

 for the most part in still repose. Some were still moving 

 to and fro, however, and, in the course of the day, most of 

 them became again active. As soon as the Colepes had 

 forsaken their prey, the Monads began to gather around 

 it, cleaving to the same parts, and apparently imbibing the 

 juices; for the extruded parts still slowly decreased, until 

 at length these were reduced to about one-third of their 

 original dimensions. 



A close examination of these latter, when they had set- 

 tled to rest, showed me that they were of the species Chilo- 

 monas paramcecium. There is an indentation on one side 

 of the front, where the mouth is situated; here there is a 



