THE MOUTH AND THE TONGUE 539 



on to the pharyngeal musculature for easy degluti- 

 tion. The floor of the mouth is constituted of the 

 sublingual surfaces and encircling teeth and gums, but 

 more especially of the tongue itself (Fig. 132), which, in a 

 sense, may be looked upon as one of the most remarkable 

 and interesting organs of the body, whether we regard it 

 from a purely anatomical point of view or from that of 

 the services it performs in the economy of life and human 

 relationships. The teeth, the gums, the salivary glands, 

 and the lateral or buccal walls of the cavity of the mouth, 

 each and all perform most important functions in the 

 economy of alimentation, and in the work of enabling 

 the central organ ot the mouth, the tongue, to perform 

 its manifold work with the maximum of facility and the 

 minimum of difficulty. 



Besides the merely mechanical functions it performs in 

 this combined work, and the many important individual 

 purposes it subserves, we have become possessed, from 

 long observation and what study we could give the 

 subject, of the fixed ideas that a great central and indi- 

 vidual function of the tongue is the admixture of that 

 colloidal material represented by its fur with the com- 

 ponent parts of the food during the linguo -palatal 

 trituration, and that admixture of its fur with the food 

 represents a specific digestive function of a vitally 

 important and absolutely necessary character, inasmuch 

 as it is initial, and of large proportion, in the long chain 

 of chemico-physiological phenomena constituting digestion, 

 and what follows. 



We have already elsewhere endeavoured to trace the 

 passage of pituitary debris from within the pituitary 

 outfall structures along the tonsillar bodies into the 

 tongue, and we have recognised in the capillary eminences 

 of the lingual mucosa the orifices of lingual excretory 

 ducts, necessitated by the existence in the tongue of this 

 residual cerebral debris or pituitary excretion, removed 

 hither for purposes of cerebral hygiene and neural or 

 neuro-systemic freedom, so to speak. Besides these im- 

 mediately important functions, basing our deductions on 

 analogies supplied within the alimentary canal throughout 

 its whole extent, and on the great axiomatic principle that 



