ORGANIC MECHANISM. 59 



malcule resemblino; an eel in its shape, which infests dis- 

 eased wheat, and which, when dried, appears in the form 

 of a fine powder: on being moistened it soon resumes its 

 living and active state.* The Gordius aquaticiis, or hair 

 worm, which inhabits stagnant pools, and which remains in 

 a dry and apparently lifeless state when the pond is evapo- 

 rated, will, in like manner, revive, in a very short time, on 

 being again immersed in water. The same phenomenon is 

 exhibited by the Filaria, a thread-like parasitic worm, in- 

 festing the cornea of the eye of the horse.t 



Both the composition of the fluid and the texture of the 

 solid parts of animal and vegetable bodies are infinitely va- 

 ried, according to the purposes they are designed to serve in 

 the^conomy. Scarcely any part is perfectly homogeneous; 

 that is, composed throughout of a single uniform material. 

 Few of the fluids are entirely limpid, and none are perfectly 

 simple in their composition; for they generally contain more 

 or less of a gelatinous matter, which, when very abundant, 

 imparts to them viscidity, constituting an approach to the so- 

 lid state. Many fluids contain minute masses of matter, ge- 

 nerally having a globular shape, which can be seen only by 

 means of the microscope, and which float in the surround- 

 ing liquid, and often thicken it in a very sensible manner.! 

 We next perceive that these globules have, in many instances, 

 cohered, so as to form solid masses; or have united in lines, 

 so as to constitute fibres. We find these fibres collectins: 

 and adhering together in bundles; or interwoven and agglu- 

 tinated, composing various other forms of texture; sometimes 

 resembling a loose net-work of filaments; sometimes consti- 

 tuting laminae or plates; and, at other times, both plates and 

 filaments combining to form an irregular spongy fabric. 

 These various tissues, again, may themselves be regarded as 

 the constituent materials of which the several organs of the 

 body are constructed, with difierent degrees of complication, 



* See a paper on this subject by Mr. Bauer, Phil. Trans, for 1823, p. 1. 

 f Blauivillc, Annates des Sciences Naturelles; X. 104. 

 + Globules of this description have been found in the lymph, the saliva, 

 and even in the aqueous humour of the eye. 



