1897. COPE'S ''FACTORS OF EVOLUTION." 43 



stage with his case of the impressed zone of the Nautiloidea, of which 

 an account was given in Natural Science, vol. Ill, p. 408. " There 

 is " says this palaeontologist " every reason for regarding the impressed 

 zone as a ctetic [i.e. acquired] characteristic acquired in the later 

 stages of growth and not hereditary so far as is known in any shells 

 of the earlier Paleozoic periods." Admitting this, one still remains 

 without definite proof, atid it is unfortunate that even Professor Hyatt, 

 in a subsequent note, has to admit certain exceptions, of which " it 

 is impossible to say at present whether the impressed zone appeared 

 as a genetic character or as a mechanical necessity." Here again the 

 evidence, however cumulative, will receive from the Neo-Darwinian 

 the same explanation as the evidence from embryology. 



The evidence from breeding is quoted chiefly from Professor W. 

 H, Brewer, and puts the case very strongly. It is pointed out that 

 " all the best breeders recognise the rule laid down by Darwin, that 

 those characters are transmitted with most persistency which have 

 been handed down through the longest line of ancestry." Hence, they 

 do not expect modifications produced by temporary conditions, or by 

 conditions that have been in operation for only a short period, to be 

 inherited. On the other hand, says Brewer, " The art of breeding 

 has become in a measure an applied science ; the enormous economic 

 interests involved stimulate observation and study, and what is the 

 practical result ? This ten years of active promulgation of the new 

 theory has not resulted in the conversion of a single known breeder 

 to the extent of inducing him to conform his methods and practice to 

 the theory. My conclusion is that they are essentially right in their 

 deductions founded on their experience and observations, namely, 

 that acquired characters may be, and sometimes are, transmitted." 

 The cases of inheritance of injuries cited by Brewer appear well 

 authenticated, but what is the use of them when they can so easily 

 be explained away, by Neo-Darwinians, as mere coincidences ? A 

 case more akin to what would, on the hypothesis of the inheritance 

 of modifications, be the action of nature, is the following : Sheep 

 taken from Ohio, where the wool is fine and good, to the alkaline soil 

 of Texas, have their wool rendered harsh in texture, while its 

 behaviour under dyes is altered. So far this is a case of undoubted 

 modification due to environment. The offspring are born with wool 

 of the same harsh character, and this alone might be explained as a 

 modification induced afresh in each generation. But it is noticed 

 that the harshness increases with succeeding generations, and flocks 

 that have inhabited such regions for several generations produce a 

 harsher wool than do the new-comers. It thus appears that there is 

 something more than a mere repetition of the modification, and this 

 something more is explained most naturally as due to inheritance of 

 the modification. To explain it as "a congenital adventitious 

 variation coincident in all the individuals of immense flocks, is a 

 mathematical absurdity." The only possible alternative appears to 



