NERVE INFLUENCE ON SECRETION. 125 



with difficulties, and can hardly as far as I can see, be 

 reconciled with the numerous facts, which show, not 

 only mere quantitative alteration of secretion and nutri- 

 tion, from altered supply of blood produced by efferent 

 nerve irritation, but also alteration of quality. 



The fact of the influence of motor nerves on glan- 

 dular secretions is now universally recognized, and the 

 flow of saliva from stimulating the distal end of the 

 cut chorda tympani has become a stock experiment in 

 the class-room. Beale refers this solely to the increased 

 supply of blood to the secreting protoplasm masses 

 caused by the influence of the nerves on the capillaries. 

 But against this view is urged the fact that stimula- 

 tion of the sympathetic nerve fibres supplying the 

 gland, likewise increases though not to the same 

 extent the flow of saliva, although at the same time 

 it causes contraction of the capillary arteries with 

 a diminished flow of blood through the capillaries ; 

 the quality of the secretion is at the same time altered, 

 and it is rendered more viscous and richer in salivary 

 corpuscles. It is, therefore, quite possible that the 

 chorda saliva results from the action of nerves on the 

 vessels, while that of the sympathetic, from action on 

 the secreting protoplasm, as supposed by Pflliger and 

 others. Besides the above, we may adduce Lud wig's 

 experiment of exciting secretion in a gland cut out of 

 the body by nerve stimulation, although no blood was 

 present. To these I have seen no answer by Beale, but 

 I believe his chief reason for dissenting from this view 

 rests on the anatomy of the question ; for, as we have 

 seen, he denies that the nerve fibres ever terminate in 

 the glandular protoplasm. Without questioning the 



