CEREBRO-SPINAL LYMPH 33 



to the terminal expansions of the individual nerve fibres, 

 thus securing their uninterrupted development and subse- 

 quent untrammelled functional role. As this fluid secures 

 .an entrance into every extra-, intra-, and inter-nervine 

 space, so it maintains throughout life a more or less 

 complete possession of these spaces, and only retires 

 in obedience to anatomical requirements and hydrostatic 

 necessities, thus continuing to perform the original func- 

 tions for which it was elaborated and stored and is still 

 so well adapted to perform, as well as that of affording a 

 means of excretion by its many guarded exits of the effete 

 materials shed into it by the katabolic results of nervine 

 waste. Moreover, we see in this "maintenance of pos- 

 session" of these inter-, extra-, and intra-neural spaces, 

 that a great provision is secured for the regular supply of 

 4 ' ready-made " lymph to such organs as the eyes and ears, 

 which constantly utilise a somewhat large amount, and 

 many of the glandular structures, oral and gastric, which 

 .are constantly, or periodically, active in the economy of 

 alimentation and other functions. 



We thus perceive that the functions of the cerebro- 

 spinal lymph range themselves into active and passive, 

 accordingly as they are physiological or mechanical, and 

 realise that the uninterrupted performance of these func- 

 tions becomes of the greatest moment in the maintenance 

 of a physiologically perfect state of health and the preser- 

 vation of the classic condition, mens sana in corpore sano^ 

 .Surgical technique must, therefore, include the preserva- 

 tion of the natural channels of exit of this fluid in the 

 many procedures implicating the nervous system, and be 

 ready to supply substitutes, if necessary, for the discharge 

 of physiological function when that has been placed in 

 abeyance either by disease or accident. 



The distribution of the cerebro-spinal fluid at the 

 different stages of embryonic and early foetal growth, and 

 the different periods of adult life, undergoes a more or 

 less continuous change and fluctuation, both in regard to 

 relative quantity and quality ; thus, on the accomplishment 

 of the neurenteric differentiation in the earliest embryonic 

 stages of life it is relatively large the central nervous 

 system then only existing as a thin, elongated vesicle, filled 



