ANIMAL. 



123 



agency of which they have been created. 

 Inorganic bodies exist through the absence of 

 all change in their interior; organized beings 

 exist by force of change : there are two pro- 

 cesses, one of renewal, the other of decom- 

 position, perpetually going on within them ; 

 they are continually appropriating from bodies 

 exterior to themselves a quantity of matter 

 which they have the singular faculty of ela- 

 borating into their proper substance, and they 

 have at the same time the power of withdraw- 

 ing portions of the matter which already forms 

 them, and rejecting these from their interior as 

 no longer fitted for their preservation. Vege- 

 tables, by means of their roots and their leaves, 

 draw from the earth and from the air materials 

 which they elaborate into juices fitted for their 

 nourishment, at the same time that they throw 

 off, especially by means of their leaves, a por- 

 tion of the matter which had been absorbed, 

 either as superfluous or as improper to enter into 

 their composition. In the same manner ani- 

 mals appropriate to themselves various amounts 

 of matter in the shape of atmospheric air and 

 food, from which they prepare a fluid proper 

 for their maintenance, at the same time that 

 they, by virtue of peculiar processes, with- 

 draw from their bodies such portions of mat- 

 ter as have already fulfilled their destination, 

 and cast them out under the form of excre- 

 tions. Organized bodies, consequently, are 

 preserved as individuals by a process of nu- 

 trition, a process which implies dependence 

 on other bodies, and alternate appropriation 

 and rejection of the particles of these ; the ex- 

 istence of an organized being, in fact, only con- 

 curs with the presence and appropriation of 

 substances external to itself, with a perpetual 

 accession of matter on the one hand, and of its 

 rejection on the other, whilst unorganized 

 bodies are more certainly continued, as their 

 state of isolation or abstraction from all ex- 

 ternal influences is more complete. Organized 

 beings, in a word, continue to exist by virtue 

 of certain inherent especial powers ; un- 

 organized simply by virtue of the general 

 powers that pervade the universe in harmony 

 with which they were originally framed. 



The modifications xuidergone by organized 

 and unorganized bodies are peculiar and cha- 

 racteristic in each class. In the first place 

 modification or change is no necessary con- 

 dition to the existence of an unorganized body, 

 as it is of one that is organized. A mineral in 

 a state of complete isolation might remain 

 eternally unchanged ; a plant or an animal, on 

 the contrary, cannot be conceived as existing 

 for a moment abstracted from the universe 

 around it, and without undergoing change. 

 A mineral, in the instant of its formation, 

 acquires all the properties that distinguish it at 

 any after-stage of its existence ; in plants and 

 animals, on the other hand, as we witness an 

 origin, so we observe a series of modifications 

 denominated ages, they commence their ex- 

 istence, they increase in size, they attain ma- 

 turity, and they decline and ultimately die. 



Any change which unorganized bodies ex- 

 hibit is accidental, and happens under the 



influence of agencies external to themselves ; 

 the changes which organized beings undergo 

 in the course they run from incipience to their 

 end, are on the contrary necessary, and take 

 place in consequence of powers inherent in 

 themselves. 



Any change which an unorganized body ex- 

 periences happens on its surface : its mass is 

 increased or diminished by simple addition to 

 or subtraction from its particles ; it does not 

 increase, neither does it shrink and decay in 

 all its parts like plants and animals, in which 

 increase and diminution take place at one and 

 the same time from within and from without. 

 Increase in the unorganized world happens 

 through juxta-position, in the organic through 

 intus-susception. Organized bodies, conse- 

 quently, as they alone are generated, as they 

 alone possess powers of self-preservation and of 

 reproduction, so do they alone grow, advancing 

 necessarily from infancy to maturity and old 

 age, or exhibit what are called ages. (See AGE ) 

 Organized bodies further meet our obser- 

 vation in two different states, those, namely, 

 of health and of disease, nothing correspond- 

 ing to which is encountered in the inorganic 

 world. 



Whatever has a beginning has also an end. 

 But the mode in which organized and un- 

 organized bodies cease to be, and the influences 

 that determine their periods of being, are ex- 

 tremely different. A mineral ends when the 

 affinities that combined it, and the attraction 

 of cohesion that held its particles together, are 

 overcome. This language implies that its 

 destruction is effected by agencies external to 

 itself by the action of other bodies, and of 

 circumstances over which it has no controul. 

 The destruction of a mineral is, therefore, in 

 nowise necessary, neither is it spontaneous : 

 abstract a mineral, as we have said, from all 

 external agency, and its endurance is inde- 

 finite. 



Very different is the case with regard to 

 animals and vegetables ; as their continuance 

 depends on the process of nutrition, their end 

 hangs upon the cessation of this act; and as 

 the tenure by which they enjoy existence is 

 temporary, the machine of organization being 

 calculated to endure but for a season, their 

 death or destruction is both spontaneous and 

 necessary. Organized bodies which alone owe 

 their being to generation, which alone continue 

 their existence, reproduce their kinds, grow, 

 attain maturity, and become aged by virtue of 

 powers inherent within themselves, so do they 

 alone die. 



The period of endurance of unorganized 

 bodies may often be calculated approximatively 

 according to their masses, their densities, the 

 aptitudes of their elements to enter into new 

 combinations, &c. ; that of organized bodies 

 cannot be inferred from these or any other 

 merely mechanical principles. Indeed, data 

 from which the duration of organized bodies 

 may be estimated are altogether wanting. We 

 only know that every species has within nar- 

 row limits a period which it cannot pass; but 

 why this period should, in particular instances, 



