1911.] the Transmission of Acquired Characters. 



571 



believed to be the proper answer, these results must be explained in some 

 other way. 



In regard to this question Brown-Se'quard's experiments may briefly be 

 summarised by stating that he found, after section of the great sciatic nerve 

 in normal guinea-pigs, the appearance of a peculiar state termed by him 

 " epileptic " ; that this appeared in every instance, or in almost all instances, 

 and that in most cases the toes were lost through the animals nibbling away 

 the parts rendered anaesthetic. Of the offspring of such animals he found 

 that a very small proportion exhibited a malformation of the feet, and that 

 of these some exhibited the " epilepsy." The proportion of offspring which 

 exhibited the " epilepsy " was only 1 to 2 per cent. 



In connection with the congenital absence of toes in these offspring 

 Morgan (40), in a criticism of the experiments, notes the possibility that 

 the malformation may be due to a perverted act on the part of the mother 

 at birth. He states that he had observed an absence of the tails in 

 succeeding litters of white mice, and that this was due to the action of 

 the mother. The mother bit the tails off and devoured them. This is not 

 difficult to explain, for it probably is a perversion of the normal act whereby 

 the mother devours the placenta and nibbles off the umbilical cord of her 

 young at birth. 



The observations described in this paper, in which actual injury to the 

 toes of the young at birth was seen in the case of offspring of guinea-pigs 

 in which the Brown-Sequard phenomenon was present, strongly support 

 this view of the origin of the " congenital " malformations of the toes 

 described by Brown-Sequard. 



But this explanation may also serve to elucidate the nature of the 

 " transmission " of the phenomenon itself. The observation described above, 

 of a guinea-pig which developed the phenomenon in consequence of an 

 accidental injury to its foot, demonstrates that the condition may be caused 

 by such an accidental injury as that which may be inflicted by the mother 

 upon its young at birth. 



The experiments of Maciesza and Wrzosek (56, 57, 58) are of some 

 interest. Their conclusion, that in the offspring of guinea-pigs in which 

 the phenomenon is present section of the great sciatic nerve is followed by 

 the appearance of the phenomenon at a smaller interval of time than is usual, 

 requires some explanation. 



But their results should be received with some hesitation until statistics 

 from a larger number of experiments are available. The figures upon which 

 they base their conclusions are obtained from 27 normal guinea-pigs and 

 14 offspring only. They take as a test the interval which elapses between 



