PAST AND FUTURE OF ANIMAL LIFE 137 



1. The distinction between those characters of an 

 organism which it acquires by use or disuse during 

 its life, or which are impressed upon it by its 

 environment, and those characters which it receives 

 as a birthright from its parents or which have ori- 

 ginated in the germ from which it has sprung, was 

 not clearly perceived until Weismann's teaching had 

 taken root, but his central position is now the basis 

 of all modern work on heredity, and has introduced a 

 different temper into the believers of progress. Whilst 

 it was still possible to hold that characters or attain- 

 ments acquired during the life-time and activity of 

 the organism were commonly transmitted to its 

 descendants, a rapid and constant evolution in an 

 upward direction seemed possible for the human 

 race. Man had only to strive ; his descendants 

 would proportionally increase in virtue ; and a race 

 of men would be evolved which might know or even 

 practise the proscriptions of the Mosaic dispensation 

 from their earliest infancy. The realities of history 

 and of heredity do not sanction such dreams, and we 

 must be content to know that while man may lose 

 almost everything by the loss of a tradition, he can 

 never by vicarious effort spare his descendants the 

 pain of assiduously acquiring it by practice. When 

 we speak of the progress of man, what we are 

 really interested in is his progress in the arts of 

 civilization and refinement, but progress in these has 



