43^ SUPPOSED TRANSMISSION OF MUTIIATIONS. [VIII. 



explaining such phenomena, of course it by no means follows 

 that we must dispense with it ; or, in other words, it does not 

 follow that the transmission of acquired changes cannot take 

 place. It would be as unsafe to make this assertion as to state 

 of a ship seen at a great distance, that it is only moving by 

 sails and not by steam simply because the movement appears 

 to be explicable by sails alone. We ought first to attempt to 

 show that the ship does not possess a steam-engine, or at least 

 that the existence of such an engine cannot be proved. 



I believe that I am able to show that the actual existence of 

 the transmission of acquired characters cannot be directly 

 proved ; that there are no direct proofs supporting the La- 

 marckian principle. 



If we ask for the facts which can be brought forward by the 

 supporters of the theory of the transmission of acquired 

 characters, if we inquire for the observations which induced 

 Darwin, for instance, to adopt such an hypothesis, or which at 

 least prevented him from rejecting it, — a very brief answer can 

 be given. There are a small number of observations made 

 upon man and the higher animals which seem to prove that 

 injuries or mutilations of the body can, under certain circum- 

 stances, be transmitted to the offspring. 



A cow which had accidentally lost its horn, produced a calf 

 with an abnormal horn ; a bull which had accidentally lost its 

 tail, from that time begat tailless calves ; a woman whose 

 thumb had been crushed and malformed in youth, afterwards 

 had a daughter with a malformed thumb, and so on. 



In a great number of such cases ever}'- guarantee for the 

 trustworthiness of the statements is entirely w^anting, and, as 

 His and still earlier Kant have already said, they are of no 

 greater value as evidence than the merest tales. But in other 

 cases this assertion cannot be made without further exam- 

 ination ; and a small number of such observations can indeed 

 claim a scientific investigation and value. I shall presently 

 discuss this point in greater detail, but I wish now to lay stress 

 upon the fact that, as far as direct evidence goes, we cannot 

 bring forward any proofs in favour of the transmission of 

 acquired characters, except these cases of mutilations. There 

 are no observations which prove the transmission of functional 

 hypertrophy or atrophy, and it is hardly to be expected that 



