S4S INFTJSORY WORMS. 



rous short feelers, forming a kind of fringe round the head. One 

 of the most elegant species of vorticella is the vorticella convallaria, 

 a beautiful transparent animalcule, the body of which is formed like 

 a bell-shaped flower, and is furnished with a verj long tail or stem, 

 by which it affixes itself to whatever substance it pleases. When a 

 groupe of these animalcules is viewed by the microscope, it exhibits 

 the appearance of a set of animated flowers, alternately stretching 

 out their stems at full length, and again suddenly contracting them 

 in a spiral twist. This species is very common, and is generally 

 found attached to the stems and under suiface of the leaves of the 

 common lemna minor, or duckweed. 



But a still more elegant species is the vorticella racemosa. It is 

 found during the summer months in clear stagnant waters, attached 

 to the stalks of the smaller water plants, and other objects; to the 

 naked eye the whole groupe, on account of the great number of in- 

 dividuals composing it, is distinctly visible, in the form of a small 

 whitish spot, resembling a kind of slime or mouldiness, but when 

 placed under the microscope in a drop of water on a glass, its ex- 

 traordinary structure is immediately perceived. From a single stem 

 proceed, at' various distances, several smaller ramifications, each 

 terminating by an apparent flower, like that of a convolvulous, and 

 furnished on the opposite edges, with a pair of filaments resembling 

 stamina. The whole is in the highest degree transparent, and per- 

 fectly resembles the finest glass ; while the varying motions of the 

 seeming flowers, expanding and contracting occasionally, and turn- 

 ing themselves in different directions, afford a scene so singularly 

 curious, as to be numbered among the finest spectacles which the 

 microscope is capable of exhibiting. Each animal, though seated 

 on the common stem, is complete in itself, and possesses the power 

 of detaching itself from the stem, and forming a fresh colon) from 

 itself. 



To the genus vorticella also belongs the celebrated animalcule 

 called the wheel-animal, from the appearance which the head hi 

 some particular positions exhibits; as if furnished with a pair of 

 toothed wheels, in rapid motion : this animalcule, which is called 

 vorticella rotatoria, has long ago been pretty well described and 

 figured by Baker, in his work on the microscope : it is of a length- 

 ened shape, and of a pale brown colour, and is of such a size as to 

 be sometimes perceptible by a sharp eye, even without a glass. It 



