518 THE POSTERIOR PITUITARY AND THE NERVOUS SYSTEM. 



the cord and medulla differ greatly. Virchow, and also Fritsche 

 and Klebs, have reported hypertrophy of the medulla. The 

 spinal cord was enlarged in the case reported by Linsmayer. 

 Many observers have reported various degenerations in the 

 cord. Baruch's case was associated with symptoms of syringo- 

 myelia; Debierre gives a case with diseased posterior columns, 

 while Arnold, Dallemagne, and Tamburini have found at au- 

 topsy irregular degenerated areas in the cord, affecting, how- 

 ever, no special place with any degree of constancy. Usually, 

 as in the first two cases reported in this paper, no abnormalities 

 of either the medulla or cord are found. 



"Brain. No constant changes are found in the brain, but, 

 as is the case with every other organ of the body in acro- 

 megalia, the encephalon may be enlarged (Fritsche, Klebs, 

 Halsti), though the increase is rarely proportionately as great 

 as that of the body. Usually few microscopical changes of note 

 are found. Demonstrable cytological degenerations are absent, 

 though interstitial and vascular lesions are sometimes re- 

 ported." This paragraph appears to us to add further testi- 

 mony to the teachings of experimental physiology which tend 

 to isolate the hemispheres from the true neural tract. 



The nature of the process through which the nervous 

 energy liberated by the posterior pituitary affects nervous 

 structures suggests itself as the next subject to receive atten- 

 tion. 



THE HISTOLOGY AND PHYSIOLOGICAL CHEMISTRY 

 OF THE NEURON. 



We are first brought to inquire into the relationship be- 

 tween the modern conception of the structural composition of 

 the cerebro-spinal axis and the views we have submitted. 

 Granted, therefore, that the posterior pituitary body is the 

 seat of a process through which chemical energy is converted 

 into nervous energy, and that this constitutes the nervous im- 

 pulses which the cerebro-spinal axis transmits to the various 

 organs, how do the nerve-elements utilize this energy when 

 functionally active? 



We refer, of course, to Waldeyer's neuron as the morpho- 

 logical unit of the cerebro-spinal axis, and the processes of 



