INFUSORIAL ANIMALCULES. 9 



I have ever examined) have been taken in meadow- 

 trenches, in the slowly running water, after a summer 

 shower, and especially about the period that the first crop of 

 hay was mown. Among healthy water plants, such as the 

 Chara, Cerotophyllum, Confervas, Lemna, &c., the various 

 kinds of Vorticellina and Rotatorial animalcules may be 

 sought for with success. The stems of aquatic plants, par- 

 ticularly those of the description just mentioned, have often 

 the appearance, to the naked eye, of being encased with 

 mouldiness or mucor, which, on being examined under the 

 microscope, proves to be an extensive colony of arborescent 

 animalcules. Whenever this appearance is of a bluish- 

 milky hue, the species will mostly be those of the Vorticella 

 or Epistylis. (See the Engravings.) If you observe little 

 dark bristle-like bodies standing out among the stems, you 

 may expect them to be the Melicerta ; and the little yellow 

 gelatinous balls upon the Ceratophillum are, probably, the 

 Megalatrocha. In clear shallow pools, the Volvox glo- 

 bator (fig. 55) may be met with in vast numbers in the 

 spring of the year; and, when these are found amongst 

 Lemna, by examining them under a deep magnifying power, 

 you may often discover, within their hollow spheres, the 

 Notomata parasita, like so many white specks. The dust- 

 like stratum we frequently notice on the surface of 

 stagnant ponds, is often composed almost entirely of 

 species of the most beautiful colours, such as the Euglena, 

 Chlorogonium, Pandorina, Gonium, and Bursaria. The 

 thin shining film, which sometimes covers plants in pools 

 of water, assuming the varied hues of red, brown, yellow, 

 green, and blue, is made up also of infusorial animalcules. 

 For example those objects, which under water appear to 



