BROWN-SEQUARD'S EXPERIMENTS 145 



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." 



Again, there is some evidence which indicates that in 

 epilepsy a poison is produced in the body of the diseased 

 animal which, when injected into healthy animals, causes 

 convulsions. 1 It is thus possible that the embryos of the 

 guinea-pigs, in which epileptic fits had been produced 

 by operations upon various parts of the nervous system, 

 absorbed toxins from the maternal circulation. It is also 

 possible that such a poison may have acted directly upon 

 the germ cells before fertilisation. This is the more pro- 

 bable because " the conditions exhibited by the offspring 

 were very diverse general feebleness, motor paralysis of 

 the limbs, trophic paralysis resulting in loss of toes, cornea, 

 &c., other nervous and sensory disorders, and in some cases 

 the particular ' epileptic ' state. In a number of cases the 

 condition of the offspring was so different from that of 

 the parent, that the only common feature was that in both 

 cases there were abnormal neuroses." 2 



The extraordinary instincts observed among insects have 

 been brought forward in support of the theory that acquired 

 characters are transmitted. 3 The instincts of Ammophila 

 and Sphex, two genera of fossorial wasps, have been given 

 as particular cases. The larvae of Ammophila feed upon 

 caterpillars, those of Sphex upon crickets and grasshoppers 

 which are supplied by the female. In both cases the female 



1 Voisin and Peron, Archives de Neurologic, xxiv., 1892, and xxv., 1893 ; 

 Voisin, L'fiptteptie, Paris, 1897. 



2 Thomson, ,1. Arthur, Heredity, 1908. The excellent description and 

 criticism of Brown-Se'quard's experiments in this work have been freely drawn 

 upon in the account given here. 



3 Lord Avebury, On the Senses, Instincts, and Intelligence of Animals, with 

 Special Reference to Insects, London, 1888. 



K 



