372 



ON THE STUDY OF ZOOLOGY 



by his own knowledge, can describe them with so much vividness 

 as to enable his audience to form competent ideas concerning them. 

 The system which I repudiate is that which allows teachers who 

 have not come into direct contact with the leading facts of a science 

 to pass their second-hand information on. The scientific virus, like 

 vaccine lymph, if passed through too long a succession of organisms, 

 will lose all its effect in protecting the young against the intellectual 

 epidemics to which they are exposed. 



