TRANSMISSIBILITY OF FUNCTIONAL MODIFICATIONS 65 



inhented this peculiarity from their mother, whose tail, it was 

 asserted, had been accidentally amputated. The newspapers reported 



ofldolfT l'"'1 ^/-V"'""''' ^°^^ ''''''^'^'^ -' the standing 

 ot Rudolf \ irchow declared it to be noteworthy, and recrarded it 



as a proof, if all the details of it were correct. ' From maty s^les 

 snndar cases .^re brought forward, intended to prove that the 

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

 degeneraion 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 m 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 

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

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

 tor 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 

 Aant, and m our own day the anatomist Wilhelm His, gave their 

 verdict decidedly against such allegations, and absolutely denied any 

 inheritance of mutilations ; and now, after h 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 m a position to give a decided negative and say there is no 

 inheritarue 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 

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

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

 inyestigation 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 off;' 

 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 off of the 

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



TT ° 



II. J, 



