180 OUTLINES OF EVOLUTIONARY BIOLOGY 



cats. Moreover, there appears to be considerable difference of 

 opinion as to whether or not the effects of circumcision are ever 

 inherited. Darwin, in discussing this point, 1 admits that it is 

 possible that all the recorded cases of apparent inheritance of 

 such effects may be accidental coincidences, but the fact that 

 there are such recorded cases prevents us from accepting the 

 sweeping generalization which Weismann makes in the last 

 sentence of the paragraph above quoted. 



Darwin himself was convinced that the effects of operations 

 are sometimes inherited by the well known and often quoted case 

 of Dr. Brown-Sequard's guinea-pigs. In these animals not only 

 did epilepsy appear in the offspring of parents which had been 

 rendered epileptic by injury to the nervous system, but certain 

 structural modifications (e.g. loss of toes) appeared in the 

 offspring when corresponding structural modifications had been 

 produced in the parent (indirectly) by similar injury. Weismann, 

 however, endeavours very ingeniously to explain away these 

 observations, and the correctness of Brown-Sequard's results has 

 been seriously impugned. 



It cannot be denied, however, that the primd facie evidence for 

 the occasional transmission of such characters as those produced 

 by mutilation is very strong. We may allow much for coinci- 

 dence, but well authenticated cases like that of the cats above 

 referred to, and like the following, are too numerous to be all 

 explained away in this manner : 



" A person, when a boy of ten years, cut the terminal 

 phalange of the little finger of his left hand with a sickle. The 

 joint was not injured, nor was the function of the finger seriously 

 impaired. There was, however, an obvious deformity. The 

 finger was ill-shaped and crooked, and the nail abnormal. He 

 married and had two children, the first a son, with normal 

 fingers, the second a daughter, who had the little finger of the 

 corresponding (the left) hand deformed from birth in the same 

 manner. The function of the finger was not seriously injured, 

 but the deformity was precisely the same in shape, even to the 

 malformation of the finger-nail. She died at thirty, without 

 children, consequently no observation on a succeeding generation 

 could be noted. None of his other kindred had malformed 

 fingers, nor had any ancestor of the child for at least three 

 generations, and there was no knowledge of any such in the 

 more remote ancestry. 



" Animals and Plants under Domestication " (2nd Ed., 1882), Vol. I., p. 467. 



