ORDER PACHYDERM ATA. ■ 393 



strated to be true,* and the excessive difficulty of such a 

 demonstration will, for a long period, render it impractic- 

 able. A theory of this description cannot be allowed to 

 rest on mere negative analogies, on suppositions which are 

 liable every moment to be destroyed by some new fact, some 

 hitherto-undiscovered phenomenon of existence. 



There are, however, other phenomena, in which with more 

 foundation, and resting on surer analogies, we may form 

 an hypothetical explanation of instinctive actions. These 

 are the phenomena of habit. The habit of performing any 

 action consists in the repetition of the corporeal act, with- 

 out effort, and without any consciousness of the intellectual 

 act which has been its primitive cause. The intellectual 

 power, stimulated by some want or desire, originally set in 

 motion the corporeal organs ; but in the course of time an 

 immediate dependence comes to be established between 

 them and the same want or desire, so that the interven- 

 tion of the mind is no longer necessary to the production 

 of the action : in this case, the action is no longer composed 

 of an act of the mind, and an act of the body, but merely 

 of the last, under the influence of the exciting cause, which 

 originally gave birth to both. Almost all our actions may 

 assume this character of habit, of which the slightest ex- 

 amination will afford us abundance of proofs. 



Now if nature should have originally established this 



* It may be remarked here, that the observation of instinct in 

 animals seems to give a fatal blow to Messrs. Gall and Spurzheim's 

 system of protuberances. Innate propensities, say these gentle- 

 men, are marked by corresponding bumps on the head. But how- 

 account, upon this system, for the wonderful instincts of many 

 insects, mollusca, and other species that are acephalous. In the 

 acephala, and a multitude of other insects, remarkable for the 

 vividness of their instincts, there is no brain, properly speaking. 

 If an animal have no head, it can have no bumps upon the head, 

 and consequently, according to Dr. Gall, no innate propensity, 

 no determination to any mode of action, no instinct. 



