THE SUPPOSED TRANSMISSION OF MUTILATIONS. 429 



caudal vertebrae, as the so-called ' soft tail.' These characters were 

 shown to have been inherited from the mother and to have under- 

 gone progressive development as regards the number of missing 

 vertebrae and the proportion of individuals with rudimentary tails. 



In a third instance Bonnet found that four to seven of the normal 

 caudal vertebrae were absent, and that the column in the region of 

 the tail was characterised by a tendency towards premature anchy- 

 losis along its whole length and not merely in its distal portion. 

 Furthermore the last three to four vertebrae were distorted and 

 were either placed transversely to the long axis of the tail, or were 

 so greatly curved that the tip of the tail was directed forwards. 



It is obvious that these changes are not such as we should expect 

 as a result of the transmission of the mutilation of the tail which 

 is so commonly practised. If the artificial injury were transmitted 

 we should not expect that a variable number of the mesial ver- 

 tebrae would be absent, but rather those of the tip. There would 

 be no reason why the existing vertebrae should be degenerate as in 

 the majority of the caudal vertebrae of the dogs examined by 

 Bonnet. 



Entirely similar phenomena have been observed by Doderlein in 

 the tailless cats which not infrequently occur in Japan. In these 

 cats the rudimentary vertebrae of the tail were reduced to a short, 

 thin, inflexible spiral, which formed a knot densely covered with 

 hair on the posterior part of the animal. 



Such a reduction of the tail occurs quite independently of 

 artificial injury, in individuals of which the parents were not 

 injured : it is even found in races, such as the dachshund, which, as 

 far as we know, have never been habitually mutilated. 



But the fact is rendered especially interesting because the 

 reduction of the vertebral column in the region of the tail takes 

 place in very various degrees. Sometimes only four vertebrae are 

 absent, sometimes as many as ten. The degree of abnormality in 

 shape and the degree of coalescence between the vertebrae also 

 differ greatly. Hence Bonnet rightly concludes that a slow and 

 gradual process of reduction is going on in these animals, a process 

 which tends, as it were, to shorten the tail. I intentionally say 

 ' as it were,' for of course the statement must not be taken literally, 

 and we must not conclude that the process of reduction is a con- 

 sequence of some hypothetical developmental force seated in the 



