EXTRACT VI. 



ON NERVINE, OR NEURONIC, SECRETION, AND INTRA, 

 FIBRAL CIRCULATION OF THE WHITE, OR MEDUL- 

 LARY, AND THE AXIS CYLINDER SUBSTANCES, 

 AND ON THE STRUCTURE OF SYSTEMIC NERVE 

 FIBRES, WITH THE "NODES OF RANVIER." 



As bearing on, and dovetailing with, the subject of 

 maintaining a proper circulation and " pressure equi- 

 librium " within and without the nervous system in its 

 widest aspects, a few of the ways in which excretion is 

 secured from that system may be shortly described, in 

 supplement of what has already been incidentally said 

 when alluding to the details of cerebro-spinal circulation 

 and excretion. The first in prominence, and to some 

 extent in importance, is the nasal excretion or discharge, 

 which is more or less constant, and abundant under 

 ordinary circumstances, but which may, in response to the 

 stimuli of sneezing, blowing, and rubbing of the nose, be 

 supplemented as occasion requires (Fig. 12). 



The second consists of the tonsillo-glosso-pharyngeal 

 mucosa, and represents the local outfall, or outflow, of the 

 pituitary gland (Fig. 15). The third may be described 

 as the anal, or perineal, and may be said to be due to 

 gravitation and capillary force, aided and increased by the 

 movements of the lower extremities when in activity, and 

 regulated by the action of the muscular texture of the 

 coccygeal body and overlying anal musculature. While 

 the fourth, and greatest in extent, may be denominated 

 the general one, that is, through the peripheral endings 

 of the nerve fibrils throughout the body, as illustrated 



