65 



We shall not here explain the general characters of the two orders of 

 functions which are subservient to the preservation of the species : the 

 differences which belong to them are pointed out in several parts of this 

 work*. I shall merely observe with the authors who have considered 

 them generally, that they are in an inverse ratio to each other, so that, in 

 proportion as the activity of the assimilating functions increases, that of 

 the external functions is abated. Grimaud has, in the most complete 

 manner, illustrated this idea of the constant opposition which exists be- 

 tween those two series of actions, over which, in the opinion of that phy- 

 sician, there preside two powers which he calls loco-motive and diges- 

 tive. It is in no kind of animals more distinct than in the carnivorous, 

 which possess organs of sense of the greatest delicacy, together with 

 muscles capable of prodigious efforts, and yet powers of assimilation so 

 feeble that their food cannot be digested, unless it be composed of mate- 

 rials analogous in composition to their own organsf. 



Too much importance should not be attached to this classification like 

 all other divisions, it is purely hypothetical. All is connected together, 

 all is co-ordinate in the animal oeconomy ; the functions are linked toge- 

 ther, and depend on one another, and are performed simultaneously; all 

 represent a circle of which it is not possible to mark the beginning or the 

 end. In circulum abeunt (Hippocrates.) In man, while awake, digestion, 

 absorption, circulation, respiration, secretion, nutrition, sensation, mo- 

 tion, voice, and even generation may be performed at the same time ; but, 

 whoever in the study of the animal oeconomy should bestow his attention 

 on this simultaneous exertion of the functions, would acquire but a very 

 confused knowledge of themj. 



By becoming familiar with these abstractions, one might soon mistake 

 them for realities; one might even go the length of seeing two distinct 

 lives in the same individual ; one would be apt to assign as the character 

 of internal life, that it is carried on by organs independent of the will. 

 Althongh this faculty of the soul presides over the phenomena of respi- 

 ration, of mastication, of the expulsion of the urine and faeces, one might 

 consider life as intrusted to unsymmetrical organs, although the heart, the 

 lungs, and the kidneys, are evidently symmetrical; one might fancy it to 



* Especially in the account of living beings, V. of the Preliminary Discourse ; arti- 

 cles sleep said fetus. It is impossible at present to go over all these distinctions, without 

 entering into useless and disagreeable repetitions. Authors Note. 



f In carnivorous animals, the power of digestion is exceedingly weak ; but their mus- 

 cles are very powerful. This relative force of the muscles was necessary in carnivorous 

 animals; as they live by depredations and slaughter, as their instinct, 'in unison with 

 their organization, sets them constantly at war with every thing that has life, and as their 

 subsistence depends on their being victorious in the battles to which Nature incessantly 

 calls them. GmMAun/r^ jlfemoir on Nutrition Author's Note. 



t The division which I lay down, is not to be strictly adopted, and as being absolutely 

 true. It is a mere hypothesis to be attended to, only in so far as it assists in arranging 

 one's ideas in a more orderly manner. For, every arrangement, even when arbitrary, 

 is useful in laying before us a great number of ideas, and in thereby facilitating the com- 

 parison that is to be instituted among them. All the acts of Nature are so connected, 

 and are linked together in so close an union, and she passes from the one to the other, 

 by such uniform motions, and by gradations so insensible and so adjusted, as to leave 

 no space rbr us to lay down the lines of separation, or demarcation, which we may 

 choose to draw. All our methods of classing and arranging the productions of Nature, 

 are mere abstractions of the mind, which does not consider things as they really are, 

 but which attends to certain qualities, and neglects or rejects all the rest. 

 Lectures on Plntsiol*:?". Jluth r >r y fs Note. 



