OBSERVATIONS AND EXPERIMENTS 219 



fications in pattern and colouring and even in the 

 shape of wings and legs. Fisher cross-bred them, 

 raising the pupae of the second generation in a normal 

 temperature. Still, many of the hybrids presented 

 some of the characters produced by a low temperature. 



In this case distinct characters were transmitted to 

 the offspring, for a modified wing is not merely a 

 symptom of a defective condition. Here we have a 

 bona fide example of hereditary transmission of a char- 

 acter acquired under the influence of the environment. 



And yet, uncompromising Anti-Lamarckians would 

 reject this evidence, for there is no proof that the 

 action of a low temperature did not exert itself simul- 

 taneously on the soma cells and on the germ cells. 

 We have already stated that this .objection did not 

 seem to us to carry any weight as far as the deter- 

 mination of the factors of evolution went, but as it 

 has a certain importance from the point of view of the 

 theories of heredity, and as it is always brought for- 

 ward in controversies of this kind, we must find other 

 examples which are not open to this criticism. 



One of the most accurate and most remarkable ex- 

 periments was made by Cunningham on flat fishes, 

 flounders and soles. Those fishes are asymmetrical, 

 one side of their body being coloured, the other un- 

 coloured, and both eyes being on the same side. This 

 curious conformation is due to the fishes' mode of life. 

 Symmetrical and bilateral when young, they later on 



