288 Habit and Instinct. 



which the evolution of truly congenital instinctive activities 

 has been effected ; not to decide between them. The first 

 is based on the hereditary transmission of acquired modifi- 

 cations of activity; the latter is based on congenital 

 variations in definiteness. Both factors may be accepted, 

 as they were, indeed, by Darwin and by Eomanes ; some 

 instincts being regarded as due to the first, others as due 

 to the second, and yet others as due to the combination of 

 the two, being, in fact, as Eomanes phrased it, of blended 

 origin. The tendency of modern biological thought in 

 Germany and in England, under the influence of Professor 

 Weismann's writings, has been towards the latter view — 

 that which denies the transmission of definiteness which is 

 acquired. And whatever may be the result of our discussion 

 of the matter, it cannot be denied that Professor Weis- 

 mann's contention has done great service in forcing us to 

 examine and test our facts with renewed and added care. 



It is questionable whether there is much to be gained 

 by considering at any length what may appear to be the 

 general biological advantages of the one view or the other. 

 The transmissionist, on the one hand, claims that his con- 

 ception of organic nature has the advantage of relative 

 simplicity ; he contends that, so long as the conditions of 

 life remain uniform, the resulting uniformity of habits will 

 ensure as much congenital stability as can be of advan- 

 tage to the race ; while under changing conditions of 

 life the breaking up of this stability through the trans- 

 mitted effects of new habits is decidedly advantageous to 

 the species, and must contribute not a little to racial 

 progress. On the other hand, the non-transmissionist, 

 after a reminder that transmission is not only not proven, 

 but, if it exist, is difficult to explain on the basis of our 

 present knowledge of the relation of the germinal cells to 

 the other bodily tissues, argues that if the organic progress 



