574 Mr. Graham Brown. Alleged Specific Instance of [Dec. 9, 



the time at which the great sciatic nerve is cut and that at which the 

 first appearance of the Brown-S^quard phenomenon is observed. This 

 interval is found to be less on the average in the offspring of guinea-pigs 

 which have the phenomenon in consequence of section of the great sciatic 

 nerve than it is in normal guinea-pigs. Of the 14 offspring upon which 

 their results are based one exhibited the " complete " phenomenon as early 

 as the fifth day after section of the nerve, and another as late as the sixty- 

 second day. With so great a variation no great value can be placed upon 

 so small a number of results as 14. For instance, had they obtained two 

 additional offspring, each of which exhibited the " complete " phenomenon 

 upon the sixty-second day, the average for the whole would nearly have 

 approached that which they obtained in the case of normal guinea-pigs. 

 An additional criticism may be directed to their results in that they compare 

 an average obtained from normal guinea-pigs with one obtained from the 

 offspring of guinea-pigs which exhibited the phenomenon, but do not compare 

 the latter average with that of their individual parents. 



Even if it can be demonstrated without doubt that the offspring of 

 " epileptic " parents on an average exhibit the phenomena within a shorter 

 duration of time after section of the great sciatic nerve than did their 

 parents, this would not necessarily prove that the state of raised excitability 

 of the scratch-reflex is inherited. 



The experience of the present author, and of Taft, and of Maciesza and 

 Wrzosek, has shown that guinea-pigs which exhibit the phenomenon are 

 unfitted to bear healthy young. Many of their young are dead at birth, 

 many are aborted, many die shortly after birth. Those which survive are 

 often less healthy than are the young of normal animals. One of the signs 

 of this ill-health may be the absence of an efficient grooming of the skin. 

 Lice may be more numerous upon them in consequence of this, and perhaps 

 also in consequence of a greater direct infection from the mother than usual. 

 This in itself will raise the excitability of the scratch-reflex. In this 

 connection Prof. Sherrington has called my attention to the fact that 

 " dirty " cats are more likely to exhibit the scratch-reflex after decapitation 

 than are .well kept ones. In a similar manner, it might be supposed that 

 the young of " epileptic " guinea-pigs would exhibit the phenomenon within 

 a shorter duration of time after section of the great sciatic nerve than would 

 the offspring of healthy individuals. 



VII. Summary. 



1. The Brown-Sequard phenomenon (" experimental epilepsy " in 

 guinea-pigs) is nothing more or less than a specific instance of the 



