LAMARCK' S THEORY OF DESCENT 



335 



special propensities to which we give the name of 

 instinct.* 



" This propensity of animals to preserve their habits 

 and to renew the actions resulting from them being 

 once acquired, is then propagated by means of repro- 

 duction or generation, which preserves the organiza- 

 tion and the disposition of parts in the state thus 

 attained, so that this same propensity already exists 

 in the new individuals even before they have exer- 

 cised it. 



" It is thus that the same habits and the same 

 instinct are perpetuated from generation to genera- 

 tion in the different species or races of animals, with- 

 out offering any notable variation, f so long as it does 

 not suffer change in the circumstances essential to 

 the mode of life." 



* " As all animals do not have the power of performing voluntary 

 acts, so in like manner instinct is not common to all animals ; for 

 those lacking the nervous system also want the organic sense, and 

 can perform no instinctive acts. 



" These imperfect animals are entirely passive, they do nothing of 

 themselves, they have no wants, and nature as regards them treats 

 them as she does plants. But as they are irritable in their parts, the 

 means which nature employs to maintain their existence enables them 

 to execute movements which we call actions." 



It thus appears that Lamarck practically regards the lowest animals 

 as automata, but we must remember that the line he draws between 

 animals wit4i and without a nervous system is an artificial one, as some 

 of the forms which he supposed to be destitute of a nervous system 

 are now known to possess one. 



\ It should be noticed that Lamarck does not absolutely state that 

 there are no variations whatever in instinct. His words are much less 

 positive : " Sans offrer de variation notable '' This does not exclude 

 the fact, discovered since his time, that instincts are more or less varia- 

 ble, thus affording grounds for Darwin's theory of the origin of new 

 kinds of instincts from the "accidental variation of instincts." Profes- 

 sor James' otherwise excellent version of Lamarck's view is inexact and 

 misleading when he makes Lamarck say that instincts are "perpet- 

 uated without variation from one generation to another, so long as 

 the outward conditions of existence remain the same " ( The Principles 

 of Psychology, vol. ii., p. 678, 1890). He leaves out the word nota- 

 ble. The italics are ours. Farther on (p. 337), it will be seen that 

 Lamarck acknowledges that in birds and mammals instinct is variable. 



