128 TJie Microscope. 



styles and undni, or little hooks. They are also 

 described at considerable length by Mr. Gosse, in his 

 most interesting book, " Evenings at the Microscope." 

 The swan-like creatures appear somewhat similar to, 

 but not identical with, an animalcule represented in 

 Mr. Gosse's book and elsewhere as " Trachelocerca 

 olor." 



And now we turn to the rotifer ; and in so doing 

 we get at once (it would seem) into very high com- 

 pany. They are as far removed in complexity of 

 structure from the other animalcules which we have 

 been considering, as the mosses are from the very 

 simplest plants; yet they have ever been described 

 along with their humbler neighbours. Had they a 

 voice to complain of this treatment, we could but 

 make an answer similar to that which Esop's husband- 

 man made to the expostulating stork, " Show me your 

 company, and I'll tell you what you are;" an ani- 

 malcule, though possessing various exalted character- 

 istics. For, in the wheel-animals, we witness what 

 the learned call a " differentiation " of parts and tissues, 

 and a " specialization" of organs. The head is plainly 

 distinguishable from the body, the skin or integument 

 is distinctly different from the internal tissues, "we 

 can detect a nervous ganglion or miniature brain, the 

 gizzard in a complicated piece of vital mechanism, 

 such as we have not met with before, and in various 

 parts of the transparent inside we see organs to which 

 particular functions are assigned."* 



The rotifers form a numerous tribe, and many 



* " Marvels of Pond-Life," p. 35. 



