EXTRACT IX. A. 



THE LESSER CEREBRO-SPINAL LYMPH EXCRETORY 

 MECHANISMS, OTIC, OPTIC, AND OTHERS. 



THE question here presents itself Do we see, in the 

 reputed secretory structures of the dual auditory apparatus, 

 productive machinery and raw material enough, so to 

 speak, to meet their large requirements ? and in answer to 

 it we think we are warranted, in the presence of the 

 suggested deficiency, in saying, at the least, that we ought 

 to look for means whereby, in case of necessity, they can, 

 or may, be supplemented. 



In looking for such means we think we have found 

 them in the passage of " ready formed" cerebro-spinal 

 fluid or lymph through the internal auditory meatus 

 (Fig. 43), along the inter-meningeal spaces and coverings 

 of the auditory nerves, which coverings become continuous 

 with the periosteum and membranous textures of the 

 inner ears their inter-spaces likewise becoming continuous 

 with the peri- and endo-lymph spaces, their respective fluid 

 contents commingling and forming common reservoirs. 

 Thus, we think, is provided a supplementary or, more truly, 

 a wholesale lymph supply sufficient for all the requirements 

 of the auditory apparatus, and which, as long as a physio- 

 logical condition of the structures and fluids concerned is 

 maintained, can be relied upon. 



The cerebro-spinal lymph enters the hollow structures 

 of the inner ears in the manner mentioned, and leaves * 

 them by certain lymph channels, described in text-books 

 on the subject, as well as, we think, by the reputedly blind 

 endolymph ducts, which leave the skull and exude, or 



