174 THE MECHANICAL FUNCTIONS. 



multitucli s of infusoria of this description.* The 

 fossil remains of several species of microscopic 

 plants, in the form of a siliceous powder, have also 

 been found in great abundance in various places. t 

 Besides possessing extensive powers of loco- 

 motion, the infusoria manifest in several of the vital 

 functions, as we shall hereafter find, a degree of 

 complication, which appears to entitle them to a 

 higher station in the animal scale, than that which 

 most naturalists have assigned to them. They are 

 certainly superior to the sponges or the polypi, 

 doomed by nature to be permanently fixed, like 

 plants, to the same spot ; and of which, if we con- 

 sider them as compound beings, the individual 

 animals are often so minute as to be scarcely visible 

 without the aid of the microscope. Mere size, 

 indeed, is of all the circumstances attendant on 

 organized beings, that which should least be as- 

 sumed as the criterion of complication or refine- 

 ment of structure. An object is great or small, 

 only in relation to the standard of our own limited 

 and imperfect senses ; but with reference to the 

 operations of creative power, all such distinctions 

 must vanish. There is not, as far as we have the 

 means of judging, in the colossal fabric of the 

 elephant, any structure more complicated than 

 exists in the minutest insect that crawls unheeded 

 at our feet. 



* See Turpin, Ann. Sc. Nat. serie 2, VII. 129. 



t Those discovered by Mr. Binney, under the surface of a re- 

 claimed peat bog, in Blytonlear, near Gainsborough, have the 

 appearance of minute rectangular crystals, and are considered by 

 Mr. J. E. Bowman as the indestructible remains of myriads of 

 microscopic confervse, nearly allied to, if not identical with, para- 

 sitic species now existing. 



