76 HEREDITY 



tlie ground ; and since it no longer suffices to say- 

 that acquirements cannot be transmitted, we must 

 resort to observation and experiment in order to find 

 out whether they are transmitted. 



But, on the other hand, there remains a great 

 number of acquirements, the transmissibility of 

 which is indeed inconceivable if we accept Weis- 

 mann's theory of the germ-plasm. Many of these 

 acquirements were once thought to be transmissible ; 

 many of them no one ever thought transmissible. 

 Very few students ever thought the cerebral change 

 which is implied in the acquirement of knowledge 

 to be transmissible. The manner in which such 

 a change could be reproduced in the germ-plasm 

 through the agency of the blood, or the internal 

 secretions, or the nerves, is inconceivable ; whilst, 

 in point of fact, we do not find that the child of a 

 linguist is born with the "gift of tongues." But we 

 may choose other instances, nicely graduated, so that 

 it comes to be a matter of controversy, and almost 

 of temperament, to say where the possibility of trans- 

 mission begins or ends. Some of these must be 

 noted ; but, meanwhile, let me once more insist that 

 we are now dealing with the conclusions as to the 

 transmission of acquirements that may be drawn 

 from the Weismannian assumption. We are not 

 yet dealing with actual observation or experiment. 

 Furthermore, it must be recognised that Weismann's 

 theory of heredity is the most difficult to reconcile 

 with the transmission of acquirements. If such a 

 reconciliation can here be effected, much more easily 

 can the transmission of acquirements be reconciled 

 with any other theory, such as Hertwig's.^ 



1 See Chapter IX. 



