4T0 EVENINGS AT THE MICEOSCOPE. 



difficult to obtain a fair sight of its structure. Its mar- 

 gin, however, is surrounded by short cilia ; the mouth, 

 which is a long opening on the front part, and at the 

 left side (as to the animal) of the ventral surface, is 

 fringed with long cilia, which are continually vibrating. 

 These are the organs, of the darting motion ; but the 

 creature crawls like a mouse, along the stems of con- 

 ferva, &c., which it performs by means of curved spines, 

 called uncini, near the front part, the points of which 

 are applied to the stem, and also by long stiff" styles, or 

 bristles, which project backward and downward from 

 the hinder part. Sometimes the animalcules crawl for 

 a moment back-downward, on the inner surface of the 

 glass cover, when the bases of the anterior curved 

 spines appear dilated like large spots. The spines are 

 not capable of much action, but they are rapidly used. 

 The general appearance of the creature reminds us of 

 the little Wood-louse or Armadillo of our gardens. The 

 interior of the body is occupied with a granular sub- 

 stance, in which are scattered many globular, vesicles 

 of diff"erent sizes. The animal is very transparent, and 

 almost colourless. They increase very fast by trans- 

 verse division, which is performed under the micro- 

 scope, so as greatly to increase the number under ex- 

 amination, even in an hour or two. A constriction 

 forms in the middle of one, which quickly deepens, 

 dividing the oblong creature into two of circular figure. 

 The mouth of the new one, with its vibratile cilia, is 

 formed long before separation is complete, and at the 

 same end and side as in the parent. The styles and 

 bristles then form, and the creatures are held together 

 for a few seconds by these organs, even when the 



