Philosophy of Botaa^y. 281 



concerned in nutrition, circulation, respiration, and reproduc- 

 tion, and communicate only indirectly with the hemispheres^ 

 but directly with the spinal cord, medulla elongata, cerebel- 

 lum, and corpora quadrigemina, which are the centers of the 

 organic functions. 



These divisions are fully developed in the newborn hu- 

 man infant and in perfect functional activity. Very different 

 is at the same time the slate of development of the hemi- 

 spheres, which are the seat of the sense perception in intel- 

 lectual activity. W^iile an infant shows the liveliest inter- 

 est in the means employed to gratify his physical wants, he re- 

 mains in a state of intellectual imbecility for months, and years 

 pass before he reaches maturity. The cause of this lies in the 

 circumstance that in the gray substance of the newborn in- 

 fant are, as yet, comparatively but few cells with extended con- 

 necting fibril ends, ^sot before the lapse of some time do also 

 the corresponding nerve ends of the sense organs advance 

 sufficiently to approach and come in contact with the cerebral 

 fibers. P'i.rst to develop are the olfactory, and at last the au- 

 ditory nerves, to proceed from the base of the brain upward 

 into the cortical sphere. 



Although thus the ps^-chical activities, with the awakening 

 of consciousness, are herewith initiated, the sphere of volition 

 is as yet very limited ; for, as only one-third of the hemi- 

 spheres are assigned to the reception of sense perception, in 

 which the other two-thirds are not at all concerned, these latter 

 remain yet for one whole month completely undeveloped, and 

 are yet' in no way connected with the other cerebral centers 

 and conductive structures. Not before the regions of the spe- 

 cial sense organs have completel}- finished their development, 

 commences the evolution in those belated parts. It is now 

 that millions of fibers extend from the sensual sphere into the 

 other two regions to intercross with one another, to evoke all 

 the muscular action, to combine with stored-up percepts and 

 concepts, to execute all the manifestations of the intellect, to 

 emit their command to every division of the body under the 

 control of volition. These parts are called the association 

 centers — the workshop of the mind. 



The herewith presented theory of mind is based upon the 



