84 THE MECHANICAL FUNCTIONS. 



parts. Every animal texture appears to be formed 

 from matter that was originally in a fluid state ; 

 the particles of which they are composed having 

 been brought together and afterwards concreting 

 by a process, which may, by a metaphor borrowed 

 from physical science, be termed animal crystal- 

 lization. Many of those animals, indeed, which 

 occupy the lowest rank in the series, such as 

 Medusa;, approach nearly to the fluid state; appear- 

 ing like a soft and transparent jelly, which, by 

 spontaneous decomposition after death, or by the 

 application of heat, is resolved almost wholly into 

 a limpid watery fluid,* More accurate exami- 

 nation, however, will show that it is in reality not 

 homogeneous, but that it consists of a large pro- 

 portion of water, retained in a kind of spongy 

 texture, the individual fibres of which, from their 

 extreme fineness and uniformity of distribution, 

 can with difficulty be detected. Thus even those 

 animal fabrics, which on a superficial view appear 

 most simple, are in reality formed by an extremely 

 artificial and complex arrangement of parts. The 

 progress of developement is continually tending to 

 solidify the structure of the body. In this respect 

 the lower orders of the animal kingdom, even when 

 arrived at maturity, resemble the conditions of the 

 higher classes at the earliest stages of their exist- 

 ence. As we rise in the scale of animals, we 

 approximate to the condition of the more advanced 



* Thus a Medusa, weighing twenty or thirty pounds, will, by this 

 sort of general liquefaction, be found reduced to only a few grains 

 of solid matter. Peron, Annales du Musee, torn. xv. p. 43. See 

 also a memoir by Quoy and Gaimard, Annales des Sciences Natu- 

 relles, torn. i. p. 245. 



