CH. v.] SYSTEM OF THE FORCES OF ANIMAL LIFE. 343 



an animal secreting organ, and consequently may be very pro- 

 perly termed a brain ; and thus the unnecessary multiplication 

 of terms be avoided. Many eminent men, seeing that the 

 ganglia are supplied with numerous capillaries, have concluded 

 that they have some beneficial function with reference to the 

 nerves. {Vide Haller, vol. cit. sect. 10, § 32.) 



In the second place, the brain merits the designation of 

 centre of animal forces, inasmuch as it is so constructed in 

 sentient animals, that it is adapted to the animal-sentient 

 forces ; and external impressions which are felt, are generally 

 so reflected in it by the intervention of conceptions, that they 

 put internal impressions from external sensations and sensa- 

 tional conceptions into action (34, 66) ; the operation of which 

 can be extended throughout the animal machines [nervous 

 system] of the whole body. (Part I, Chap. III.) 



Another centre of animal forces found in all animals is the 

 hearty and which is specially adapted to be such by the number 

 of its nerves and the varied composition of its plexuses (516). 

 When it is remembered that all conceptions, in so far as they 

 are pleasant or disagreeable, modify its movement (250) ; that 

 a great number of animal actions in the entire economy of 

 the organism are thus developed, as is particularly shown in 

 the sensational instincts and passions (258) ; that its natural 

 movement is maintained by means of unfelt external and in- 

 ternal impressions (459, 515) ; and that by means of the circu- 

 lation the greater number of the processes necessary to the 

 preservation of the individual are maintained, there can be no 

 doubt as to the importance of this centre of animal forces. 

 Although such a heart as the larger animals possess is not de- 

 veloped in all animals, still there is always a machine which 

 regulates the circulation of the fluids, and to which the term 

 heart may be very fairly assigned. The region of the diaphragm 

 and of the stomach is not unreasonably considered to be a 

 centre of animal forces, because numerous nerves meet and 

 unite there (171, 174) ; and because it is observed that the 

 impressions reaching there develop nerve-actions and sentient 

 actions in most parts of the body {vide § 688). Lastly, the 

 sexual organs occupy an important position amongst the centres 

 of animal forces (687) . 



674. We know of no animal with a general centre of animal 



