THE FLOUNDER AND THE PLAICE. 299 



as distinct races or no. He says not a word of Natural Selection or of 

 Laraarckian factors. We are very far from being disposed to complain 

 of these omissions. 



In his concluding paragraph the author justifies his research by 

 showing that it points to this important fact, namely, that the morph- 

 ology of an organism is not wholly dependent on internal formative 

 forces — e.g., Heredity, and Variation due to internal causes — but is also 

 directly influenced in a determinate manner by external, chemical, and 

 physical forces. The author, unless we are much mistaken, is not here 

 concerned with the causes of evolution : he is merely pointing to the 

 fact that every individual is continually subject to external influences, 

 which must have an effect on its structure, whether characters so 

 acquired are inherited or not. 



And these external influences may act directly to produce certain 

 modifications in the individual during its lifetime, or indirectly in deter- 

 mining the incidence of selection, or in both of these ways. Leaving 

 out, for the sake of argument, the possibility of inheritance of acquired 

 characters, the external conditions must still be considered of the 

 greatest import — a fact which will be appreciated when it is remem- 

 bered that an individual cannot be rightly regarded as a naked bundle 

 of characters transmitted from its parents, but as an organism endowed 

 with certain inherited tendencies, and reacting during life to the con- 

 ditions of its environment. There can be no question, then, of the 

 value of research which is concerned with the examination of the efl'ects 

 of external conditions. And this makes us regret all the more that the 

 author was not as careful in establishing his facts on a sure basis as he 

 is cautious in expressing his opinion on the theoretical aspects of tlie 

 subject. 



