THE IDENTITY OF NEUROGLIA. 551 



when we consider their proximity not only to the cell-body, 

 which contains a large supply of fibrils, but also to the axis- 

 cylinder (ax. in the drawings), which is the only centrifugal 

 channel through which the engorged plasma can escape. 



A feature of the cells shown by Figs. 1, 2, and 3 which 

 strikingly links them to the adrenal phenomena brought on by 

 toxics in the general organism is the fact that, although they 

 are derived from animals in which the doses of ricin injected 

 were reduced with each animal, the morbid phenomena as ex- 

 emplified by each cell in turn are correspondingly intensified. 

 In other words, the adult rabbit represented by Fig. 1 was given 

 subcutaneously a dose of 0.5 milligramme, and death occurred 

 in thirty-six hours: the cell only shows apical lesions. The 

 second adult rabbit was given the half of the previous dose, 

 i.e., 0.250 milligramme, and death occurred in forty-eight hours: 

 the entire apical dendrite and two of the collaterals are dis- 

 tinctly involved. The third adult rabbit was given the half 

 of the last dose: i.e., 0.125 milligramme, and death occurred 

 in seventy-two hours: the apical dendrite is markedly studded 

 with thickenings, and all but two of its collaterals have dis- 

 appeared. It is, perhaps, unnecessary to lay stress upon the 

 fact that this is due to the prolongation of the stage of adrenal 

 stimulation: i.e., of the time during which central vascular con- 

 traction caused peripheral capillary engorgement. And this 

 need not be ascribed only to ricin. Berkley emphasizes this 

 assertion when he says: "The poison ricin, whose action is in 

 many ways similar to that of many toxalbumins of bacterial source, 

 is capable of exerting a deep and extensive degenerative in- 

 fluence on the protoplasm of the nerve-cells of the brain." 

 And this may further be extended to other toxics, for he also 

 says: "Poisoning 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 

 cerebrum, very similar in character to the pathological lesions 

 produced by other more virulent poisons/' We thus have in- 

 controvertible evidence that the unity of action displayed by 

 all poisons, owing to the fact that the dynamic source of the 

 phenomena witnessed is the one adrenal system, also extends 

 to the nervous system. That the alterations in the elements 



