1911.] the Transmission of Acquired Characters. 559 



that the young which exhibited " epilepsy " had, in all cases, also 

 malformation of the toes. 



Maciesza and Wrzosek (56, 57, 58) have, still more recently, taken up the 

 investigation afresh. They found that of 82 young guinea-pigs born of 

 epileptic " parents, it was possible in 33 cases to induce " incomplete 

 epileptic " attacks by mechanical pressure applied to the skin of the neck 

 and face. They never obtained " complete " attacks. They also found that 

 in the case of young guinea-pigs, born of normal parents, it is sometimes 

 possible to induce similar " attacks." But, at the same time, they observed 

 that the date of the first appearance of either " incomplete " or " complete 

 epilepsy," after section of one great sciatic nerve, is one week earlier, in 

 the case of the offspring of " epileptic " parents, than it is in the case of 

 normal guinea-pigs. 



The same observers also investigated the possibility of the inheritance of 

 feet malformations, produced by section of the great sciatic nerve, in guinea- 

 pigs and in white mice. In the large number of offspring observed — in the 

 case of the mice over several generations — they never saw malformations 

 of the hind limbs. But, in the offspring of normal parents, they observed a 

 small number of cases where there were such malformations, in most cases 

 acquired. Amongst the offspring of normal guinea-pigs, the percentage of 

 eases in which there were malformations of the lower limbs — either acquired 

 •or inborn — was between one and two ; this percentage corresponds very 

 closely to that found by Brown-Sequard in the offspring of " epileptic " parents. 



In looking back over these results we must admit that certain observers 

 have undoubtedly observed the presence of the " complete " Brown-Sequard 

 phenomenon in the offspring of parents in which the condition was also 

 present and caused by injury to the great sciatic nerve ; and that at the 

 same time, and in the same offspring, there were malformations of the lower 

 extremities. We must also admit, however, that such malformations of the 

 hind limbs may be present, too, in the offspring of normal parents. 



II. Experiments Concerning the Nature and Cause of the Brown-SSquard 

 Phenomenon. 



(a) The Views Held by Previous Observers. — Brown-Sequard classified the 

 phenomena (22) as either " double " or " single," and as either " complete " 

 ■or " incomplete." When the phenomenon is " single," the scratching 

 movements are confined to the hind limb of that side on which the great 

 .sciatic nerve was cut. In the case of the " double " phenomenon the 

 scratching movements first occur upon that side, but later spread to the 

 other side. The terms " complete " and " incomplete " refer respectively 



