442 SUPPOSED TRANSMISSION OF MUTILATIONS. [VIII. 



Such a reduction of the tail occurs quite independently of 

 artificial injury, in individuals of which the parents were not in- 

 jured : 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 ab- 

 normality in shape and the degree of coalescence between 

 the vertebrae also differ greatly. Hence Bonnet rightly con- 

 cludes 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 state- 

 ment must not be taken literally, and we must not conclude 

 that the process of reduction is a consequence of some 

 hypothetical developmental force seated in the organism, of 

 which the purpose is to remove the tail. On the contrary, 

 this instance shows very clearly that the appearance of a 

 development guided in a certain direction may be produced 

 without the existence of any motive developmental force. 



The disposition of the tail to become rudimentary, in cats and 

 dogs, may be explained in the simplest way, by the process 

 which I have formerly called panmixia. The tail is now of 

 hardly any use to these animals ; and neither dog nor cat 

 would perish because they possessed only an incomplete tail. 

 Hence natural selection does not now exercise any influence 

 over these parts, and an occasional reduction is no longer 

 eliminated by the early destruction of its possessor : therefore 

 such reduction may be transmitted to the offspring. 



The race of tailless foxes which, according to Settegast, 

 existed during the present century on the hunting-grounds of 

 Prince Wilhelm zu Solms-Braunfels, very soon disappeared ; 

 while cats and dogs with rudimentary tails have been 

 preserved in many cases. Such results are to be expected, 

 because in these domesticated animals the absence of the 

 tail did not cause any inferiority in the struggle for existence. 



But these facts appear to me to be remarkable in another 

 direction. I previously mentioned the tailless race of Manx 

 cats. Tradition does not tell us how it happened that the 

 descendants of the first tailless cat in the Isle of Man were able 



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