374 FUNCTIONS OF THE NERVOUS SYSTEM, [ch. i. 



and just as the fluid of the pericardium, thorax, abdomen, 

 scrotum, generated from the arterial exhalation, does not require 

 special excretory ducts, but is absorbed by the absorbent veins, 

 so also beyond all doubt, is it with the fluid of the ventricles 

 of the brain. Haller conjectures, with probability, that the 

 pituitary gland is an appendix of the brain, as in fishes he 

 has seen filaments like those of nerves to pass out of it. 



SECTION VI. IT IS PROPOSED, WITH OTHER SPECIAL FUNCTIONS 



OF THE NERVOUS SYSTEM, THAT THE CORTICAL PORTION OF 

 THE BRAIN BE SUBSTITUTED FOR THE VENTRICLES AS THE 

 PART WHERE THE ANIMAL SPIRITS ARE SECRETED, AND 

 THAT THE MEDULLARY MATTER HAS THE FUNCTION OF 

 COLLECTING AND DISTRIBUTING THEM TO THE NERVES. 



The animal spirits, being ejected from the ventricles, were 

 placed in the cerebral substance ; so that Malpighi, "Willis, and 

 Sylvius de le Boi, were unanimous that they are secreted in the 

 cortical substance of the brain ; that, when secreted, they are 

 received into the medullary substance, and distributed thence 

 through the nerves to the whole body ; and this doctrine is 

 maintained by many physiologists and pathologists to the pre- 

 sent day. The faculties of the mind, such as perception, imagi- 

 nation, understanding, and memory, were banished from the 

 ventricles together with the vital spirits, and were located by 

 some in the solid mass of the brain ; by others were afl&rmed 

 to be properties of the immaterial and rational soul alone, and 

 in no wise dependent on the body. Lest I should weary the 

 reader by a lengthened enumeration of the almost innumerable 

 authors of this opinion, I will only adduce the doctrines of 

 Malpighi and Willis, and then state, in general terms, how far 

 their successors followed these celebrated men, and how far 

 they departed from their doctrine. 



Marcellus Malpighi, in his letters to Fracassatus, ' De Cerebro 

 et Cortice Cerebri,^ maintains that the cortical portion secretes, 

 by means of a glandular structure, which he pretends it con- 

 tains, a coagulable serum from the arterial blood, and that it 

 is necessary to sensation and movement, that this fluid be 

 transmitted from the cortical to the medullary matter. It 

 does not seem possible to him, that there can be a reflux of 

 this serum in the nerves to the brain so as to cause sensation, 



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