522 THE POSTERIOR PITUITARY AND THE NERVOUS SYSTEM. 



to 39 C. In his first experiment, puppies about seven weeks 

 old, sisters from the same litter were used, the one while some- 

 what tired, the other after having slept. A careful count of 

 the pyramidal cells of the cortex of the somewhat fatigued 

 puppy gave a proportion of 31.1 per cent, of cells showing 

 varicosity, while cells from the same region of the puppy killed 

 after sleeping was 8.5 per cent. In the former animal 15.9 per 

 cent, of the cells showed much varicosity; in the latter only 

 0.8 per cent, showed a similar state. In the second experiment 

 the first of two sisters was killed on waking in the morning; 

 the second at night when tired and very sleepy. While it "was 

 difficult to find a single varicosity on the dendrites of the morn- 

 ing puppy, for long distances in the cortex of the evening 

 puppy" it was difficult to find a cell "whose processes" were 

 "not more or less varicose." It is evident that in these in- 

 stances at least the stain was not alone the source of vari- 

 cosities, since it was only in the tired puppies that the vari- 

 cosities were very marked, while in the thoroughly rested 

 animal practically none could be found. 



Judging from these experiments, varicosity of the den- 

 drites coincides with a fatigued condition. This corresponds 

 exactly with the experiment of Demoor, previously described, 

 since retraction of the gemmules is accompanied by varicosity; 

 so that fatigue and a large dose of morphine must have pro- 

 duced similar results. 



If the staining process alone caused the formation of vari- 

 cosities in Demoor's experiments, the same method having 

 been used for all specimens, how is it that one of the latter 

 showed gemmules (which means absence of varicosities), and 

 that this solitary specimen is precisely from the only animal 

 which had not received morphine? Berkley 25 found that poi- 

 soning with alcohol "in considerable doses, continued over a 

 moderate time, will produce decided and ascertainable lesions 

 of the nutrient structures and nervous elements of the cere- 

 brum" very similar in character to the pathological lesions pro- 

 duced by other more virulent soluble poisons. The terminal 

 twigs of the dendrites were also found to have become varicose 



28 Berkley: Brain, Winter, 1895; and Johns Hopkins Hospital Reports, vol. 

 vi, 1897. 



