Inheritance of Acquired Characters 



blossomed, and, taken altogether, there was no 

 appreciable difference from O. repens, L" 



From this experiment Professor Henslow draws 

 the inference that acquired characters tend to be 

 inherited in plants. In our opinion the ex- 

 periment affords strong evidence against the 

 Lamarckian doctrine. Here we have a plant 

 which has, perhaps, for thousands of generations 

 developed spines owing to its dry environment. 

 If acquired characters are inherited we should 

 have expected this spiny character to have 

 become fixed and persisted under changed 

 conditions, for some generations at any rate. 

 But what do we find ? By the second year the 

 thorns have entirely disappeared. All the years 

 during which the plant was exposed to a dry en- 

 vironment have left no stamp upon it. The fact 

 that the new branches of the first year's growth 

 bore small spines is not, as Professor Henslow 

 asserts, proof of their hereditary character. It 

 merely shows that the initial stimulus to their 

 development occurred while the plant was still in 

 its dry surroundings. 



In the same way all other so-called proofs of the 

 heredity of acquired characters break down when 

 critically examined. 



In our opinion "not proven" is the proper 

 verdict on the question of the possibility of the 

 inheritance of acquired characters in the higher 

 animals. One thing is certain, and that is that 



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