TRANSMISSION OF MODIFICATIONS 401 



and apparently according to the same train of reflexes that provide 

 in life generally for such important vital processes as the pulsa- 

 tion of the heart, characteristic action of the various glands of 

 the body, the movements of the intestines, etc. All traces of 

 memory were gone, and the dog could not recognize its master. 

 It would avoid objects in walking, but could not recognize food. 

 If, however, the food were brought in contact with the nose or 

 placed in the mouth, the jaws commenced to work and the food 

 was swallowed and digested as by any other dog. 1 



Dogs in this condition live for months or for years, and perform 

 all the functions of normal animals not requiring intelligent 

 action. All this shows to what extent vital actions are a series 

 of reflexes constituting a train, in which, if one member be started 

 by appropriate stimulus, all the rest follow automatically. 



Instinct not founded on habit. The facts that have been cited 

 certainly show that instinctive acts are nothing but the putting to 

 use of parts in possession of the individual and capable of action. 

 They are in that way spontaneous, and whatever meaning or 

 special significance may seem to be involved, it is to be sought, 

 not in the impulse to the act, but farther back in the circumstances 

 and causes that led to the development of the parts, each with its 

 characteristic capacity. A multitude of causes have taken part in 

 the selective processes by which the several organs and parts of 

 a body have been developed, each capable of performing a special 

 act, either independently or as a part of a complicated series ; 

 but, once assembled, nothing is more natural than that each 

 should perform its proper service, and any stimulus sufficient to 

 start the machinery will of necessity insure the whole train of 

 appropriate results. 



Nor are we to be deceived by the appearance of intelligence 

 as the acts proceed. The busy preoccupation of the insect 

 engaged in one of the more complicated processes of egg laying 

 has all the semblance of the highest intelligence, but we must 

 not forget that in many cases the individual must be entirely 

 ignorant of the final result ; it will be dead before the eggs 

 hatch ; it lives but a single season and, therefore, neither it nor 

 its ancestors ever saw a larva ; it is simply playing its role in a 



1 Loeb, Physiology of the Brain, pp. 246-248. 



