ROWN-SQUARjyS EXPERIMENTS 235 



Jan. 15, 1896). Moreover, Voisin and Peron have found evidence 

 that in epilepsy a toxin is produced which causes convulsions 

 when injected into animals (see Archives de Neurologic, xxiv., 

 1892, and xxv., 1893, and Voisin's L'Epilepsie, Paris, 1897, pp. 125- 

 133). It is thus not a mere speculation to suppose that a toxin 

 was produced in the guinea-pig epilepsy, and that this affected the 

 germ-cells of both sexes. This suggestion is made by Prof. Bergson 

 in his remarkable book L* Evolution Creatrice (1907), and he addsi 

 to the suggestion the query, May not something of the same sort I 

 be true in those cases where acquired peculiarities are transmitted ?* 



Prof. T. H. Morgan (1903, p. 255) also notes an interesting 

 fact. " While carrying out some experiments in telegony with mice, 

 I found in one litter of mice that when the young came out of the 

 nest they were tail-less. The same thing happened again when the 

 second litter was produced, but this time I made my observations 

 sooner, and examined the young mice immediately after birth. I 

 found that the mother had bitten off, and presumably eaten, the 

 tails of her offspring at the time of birth. Had I been carrying on 

 a series of experiments to see if, when the tails of the parents were 

 cut off, the young inherited the defect, I might have been led into 

 the error of supposing that I had found such a case in these mice. 

 If this idiosyncrasy of the mother had reappeared in any of her 

 descendants, the tails might have disappeared in succeeding genera- 

 tions. This perversion of the maternal instincts is not difficult to 

 understand, when we recall that the female mouse bites off the 

 navel-string of each of her young as they are born, and at the same 

 time eats the after-birth. Her instinct was carried further in this 

 case, and the projecting tail was also removed, 



"Is it not possible that something of this sort took place in 

 Brown-Sequard's experiment ? The fact that the adults had eaten 

 off their own feet might be brought forward to indicate the possi- 

 bility of a perverted instinct in this case also." On the other hand, 

 this interpretation cannot apply to some other results which Brown- 

 Sequard observed. 



Sommer's Experiments far from corroborating Brown-Sequard's. 

 In experiments the results of which were published in 1900, Max 

 Sommer repeated some of those which Brown-Sequard and others 

 had made, but without corroborating them. 



The so-called " epilepsy " was induced by cutting the sciatic nerve 

 on one side or on both sides ; the tendency to " fits " occurred some 



