276 THE ADRENAL SYSTEM AND VASOMOTOR FUNCTIONS. 



becomes flushed." From our point of view, this applies to the 

 arteries deprived of chorda-tympani fibers, since those supplied 

 with these fibers are contracted and hidden to a greater degree 

 than before. "Before stimulation the blood trickles out in a 

 thin, slow stream of a dark, venous color; during stimulation 

 the blood rushes out in a full stream, often with a distinct 

 pulsation." Even during excessive glandular activity, the gen- 

 eral circulation remains unaffected; hence some local means 

 must intervene to greatly increase the blood-flow; a slight 

 increase of speed is doubtless afforded by the shifting of the 

 blood-stream into the glandular arterioles, but the passage of 

 the blood through the capillaries, glandular elements, etc., very 

 soon annuls this gain. Indeed, powerful pressure is required 

 to overcome these obstacles; hence the presence of vasocon- 

 strictor "sympathetic" fibers around the arteries, to reduce 

 their lumen and thus increase the vis a tergo power of the 

 blood-stream. These arteries being outside the gland, as com- 

 pared to those constricted by the chorda tympani, we will call 

 them "extrinsic" constrictor fibers in contradistinction to those 

 of the latter nerve, which we will call "intrinsic" The same 

 arrangement prevails in muscles to increase the general flow 

 of blood through them when incited to activity, and in addition 

 to the fibers distributed to the arterioles just before these give 

 off capillaries to the muscle-fibers. 



SUDORIFEROUS GLANDS. The confusion that the litera- 

 ture upon the secretion of sweat so plainly indicates in respect 

 to the mechanism of this function is easily accounted for when 

 we recall the important part taken in the process by practically 

 unknown organs: i.e., the adrenals and their consorts, the 

 anterior pituitary and the thyroid. We have seen that free 

 sweating attended the erethic stage of exophthalmic goiter, 

 and, furthermore, have ascertained that lacrymation could be 

 caused by pilocarpine as a result of the increase of blood- 

 pressure this alkaloid was able to produce. If we now recall 

 the fact that the sweating caused by it is attended with pe- 

 ripheral hyperaemia, i.e., flushing, the link with the first 

 stage of exophthalmic goiter, also essentially due to suprarenal 

 overactivity, along with its physiological sequela? (contracted 

 central vascular trunks, intense peripheral engorgement of the 



