TRANSMISSIBILITY OF FUNCTIONAL MODIFICATIONS 65 



inherited this peculiarity from their mother, Avhose tail, it was 

 asserted, had been accidentally amputated. The newspapers reported 

 that the case excited great interest, and biologists of the standing 

 of Rudolf Virchow declared it to be notewortliy, and regarded it 

 as a proof, if all the details of it were correct. From many sides 

 similar cases were brought forward, intended to prove that the 

 amputation of the tail in cats and dogs could give rise to hereditary 

 degeneration of this part ; even students' fencing-scars were said 

 to have been occasionally transmitted to their sons (happily not to 

 the daughters) ; a mutilated or torn ear-lobe in the mother was said 

 to have given rise to deformity of the ear in a son ; an injury to 

 a father's eye was said to have caused complete degeneration of the 

 eyes in his children ; and deformity of a father's thumb, due to frost- 

 bite, was said to have produced misshapen thumbs in the children 

 and grandchildren. A multitude of cases of this kind are to be found 

 in the older textbooks of physiology by Burdach, and above all by 

 Blumenbach, and the majority have no more than an anecdotal value, 

 for they are not only related without any adequate guarantee, but 

 even without the details indispensable to criticism. 



As far back as the eighteenth century the great philosopher 

 Kant, and in our own day the anatomist Wilhelm His, gave their 

 verdict decidedly against such allegations, and absolutely denied any 

 inheritance of mutilations ; and now, after a decade or more of lively 

 debate over the pros and cons, combined with detailed anatomical 

 investigations, careful testing of individual cases, and experiment, 

 we are in a position to give a decided negative and say there U no 

 inheritance of mutilations. 



Let me briefly explain how this result has been reached. 



In the first place, the assertion that congenital stump-tails in dogs 

 and cats depended on inherited mutilation proved to be unfounded. 

 In none of the cases of stump-tails brought forward could it even 

 be proved that the tail of the relevant parent had been torn or cut 

 oflf, much less that the occurrence, in parents or grandparents, of short 

 tails from internal causes was excluded. At the same time anatomical 

 investigation of such stump-tails as occur in cats in the Isle of Man, 

 and in many Japanese cats, and are frequently found in the most 

 diverse breeds of dogs, showed that these had, in their structure, 

 nothing in common with the remains of a tail that had been cut oft", 

 but were spontaneous degenerations of the whole tail, and are thus 

 deformed tails, not shortened ones (Bonnet). 



Experiments on mice also showed that the cutting ofi' of the 

 tail, even when performed on both parents, does not bring about 

 II. F 



