No. 2.] CHANGES m NERVE CELLS. 137 



In mvown experiments, even in sections of normal, resting gan- 

 glia I invariably find a few cells which have all the appearances 

 of being worked. The number of these cells in normal gangha 

 varies, but may reach five to ten per cent, while in stimulated 

 ganglia they often exceed ninety per cent. My theory was 

 fn s°uch cases that some of the cells had become more or less 

 fatigued by the ordinary activity of the ammal. This was 

 merely supposition. It might also have been supposed that 

 these cells were in process of degeneration. But after we have 

 wrapped up an animal in cotton batting and laid it m a warm 

 chamber at constant temperature for twenty-four hours, its brain 

 having been previously destroyed, so that it makes no voluntary 

 movements, after scarcely a sensory impulse has broken the rest 

 of the cells for that length of time, we find, as might be expected, 

 a, the cells in most perfect resting condition. The ceUs appear 

 uniformly full, with not a single shrunken nucleus visible. The 

 nuclei in fac , appear larger, rounder, and clearer than in any 

 spedmen I h^ve hitherto examined. It would seem, therefore 

 quite possible that the differences between ganglion cells 

 observed in sections of the same specimen, maybe due to he 

 Phase of functional activity or of nutrition in which each of the 

 cell happened to be when it died or was killed by the reagent 



No one is better aware than the writer that repetition of such 

 a series of experiments is desirable. My time and work how 

 ever d d not permit of this ; and it was thought preferable that 

 si; one else should be allowed to make the repetition, in case 

 rse experiments are not considered conclusive. Everything 

 n the work has been made as exact and mathematical as possi- 

 ble, on the one hand, in order to do away with the necessity for 

 repetition, and, on the other, to make exact repetition possible. 

 A far as tiie specimens obtained from the series are con- 

 cerned, they leave no room for questioning the two following 



conclusions : — , ^^ ^r^^rv, tV.<^ 



First, that spinal ganglion cells of kittens do recover from the 



effects of electrically stimulating the nerve gomg to them 



Second, that recovery may be a slow process. It is not com^ 



plete after eighteen hours, but is found to be about complete 



after a rest of twenty-four hours. 



Pre-eminently master among the t-ues of the animal body 



controlling their activity in so many ways, in starvation holding 



