VIII.] SUPPOSED TRANSMISSION OF MUTILATIONS. 45 1 



my position clear, I propose to discuss two further classes of 

 observations. First of all, there are very many cases of the 

 apparent transmission of mutilations in which it was not the 

 mutilation or its consequences which was transmitted, but 

 the predisposition of the part in question to become diseased. 

 Richter ^ has recently pointed out that arrests of development, 

 so slight as to be externally invisible, frequently occur, and 

 that such arrests exhibit a tendency to lead to the visible de- 

 generation of parts in which they occur, as the result of slight 

 injuries. Since therefore the predisposition towards such arrest 

 is transmitted by the germ— occasionally even in an increased 

 degree— the appearance of a transmitted injury may arise. In 

 this way Richter explains, for instance, the frequently quoted 

 case of the soldier who lost his left eye by inflammation fifteen 

 years before he was married, and who had two sons with left 

 eyes malformed (microphthalm.ic). Microphthalmia is an arrest 

 of development. The soldier did not lose his eye simply be- 

 cause it was injured, but because it was predisposed to become 

 diseased from the beginning and readily became inflamed after 

 a slight injury. He did not transmit to his sons the injury or 

 its results, but only microphthalmia, the predisposition towards 

 which was already innate in him, but which led in his sons from 

 the beginning, and without any obvious external injury, to the 

 malformation of the eye. I am inclined to explain the case 

 which Darwin in a similar manner adduced, during the later 

 years of his life, in favour of the transmission of acquired 

 characters, and which seemed to prove that a malformation 

 of the thumb produced by chilblains can be transmitted. The 

 skin of a boy's thumbs had been badly broken by chilblains 

 associated wdth some skin disease. The thumbs became greatly 

 swollen and remained in this state for a long time ; when healed 

 they were malformed, and the nails always remained unusually 

 narrow, short, and thick. When this man married and had 

 a family, two of his children had similarly malformed thumbs, 

 and even in the next generation two daughters had malformed 

 thumbs on both hands. The case is too imperfectly known 

 to admit of adequate criticism ; but one may perhaps suggest 

 that the skin of different individuals varies immensely in its 



^ W. Richter, 'Zur Vererbung erworbcncr Charaktcrc,' Biolog. 

 Centralblatt, Bd.'vill. 1888, p. 289. 



G g 2 



