Ixxxvi Journal of Comparative Neurology. 



brain a certain amount of substitution must be possible. The evidence 

 that such amitotic cell multiplication goes on m the axial lobe of rep- 

 tiles is very strong and will be treated in extenso in another place. 



[C. L. H.] 



Effects of Removal of Cerebro-splual FluW.^ 



Dr. George Halley gives details of several operations which in- 

 volved the loss of much of the cerebro-spinal fluid and decides that 

 the result is practically the same upon the greneral health as that of 

 great losses of blood. We observe that the psychical disturbance, 

 especially loss of memory and mental habitude, are pronounced and 

 that these symptoms appear very promptly. It might seem that a re- 

 sult of suddenly lowering the pressure within the cavities would be 

 corresponding hypersemia of the brain tissue itself; this, however, the 

 Doctor denies. May it not be that the cerebro-spinal pressure is an 

 essential element in filling the minute spaces and that the turgidity of this 

 system is a prerequisite to perfect nutrition, and thus to function ? It 

 seems probable from the results of injection as well as of metalic im- 

 pregnation of the brain that such fine sinuses — far too small to con- 

 vey corpuscles — are very numerous in the cerebrum. The great de- 

 velopment of plexuses, paraphyses, epiphyses and hypophyses in the 

 brain and their close relation to the blood capillaries suggests a vital 

 connection between the cerebro-spinal fluid and cerebral function. 

 It may not be too much to suggest that many of the most essential 

 elements for brain nutrition find their way to the neurons only by this 

 indirection. The function of the so-called blood-glands is rightfully 

 claiming a large share of our attention at present and in their chem- 

 ical and vital processes may be found an explanation of the remarka- 

 ble effects of the vital extracts now in vogue. 



The Influence of Psychical Phenoiuonon on Brain Temperature.^ 



Professor Mosso has investigated the heat production of the brain 

 by means of delicate thermometers which register changes of .001 

 degrees centigrade. Tracings of the temperature variations in the 

 blood of the brain, carotids and uterus are compared. When par- 

 tially narcotized, a noise produces a slight elevation of temperature, 

 while a much greater variation will be produced by the induced cur- 



^Journ. Am. Med. Soc. XXI, 3. 



^ Mosso, A. Les Phenomenes Psychiques et la Temperature des Cerveau, 

 Turin, 1892. 



