32 GENERAL PART 



lin, while pilocarpine for the most part did not cause sweating; and he regards 

 the complicated process in the vegetative nervous system in dysmenorrhea 

 as vagotonic. I do not believe that these things allow of such a grouping. 



B. Influence of the Nervous System on the Function of the Ductless 



Glandular System 



I now come to the consideration of those relations between the ductless 

 glandular system and the nervous system which are characterized by the fact 

 that the ductless glandular system is itself vegetative, that it is made up of 

 organs supplied by vegetative nerves that possess central projection-fields. 

 We shall have investigated in what measure activity of the ductless glandular 

 system is regulated by the nervous system. Our knowledge as to this kind 

 of relationship is as yet very deficient. We may scarcely put aside the sup- 

 position that in this respect the ductless glands behave very differently. The 

 impulses emanating from the central nervous system are very important 

 for the activity of the chromaffin tissue; for example, perhaps a regulated 

 activity is not possible even for a short time if the central innervation is want- 

 ing. Centers for these ductless glands lie on the floor of the fourth ventricle 

 and according to the later investigations of Aschner also in the subthalamic 

 region. Stimulation of these centers leads, just as the stimulation of the 

 nervous paths proceeding from them to the chromaffin tissue, to the dis- 

 semination of adrenalin. Priestley and / have shown that after interruption 

 of these paths by transection of the lowest cervical cord the amount of sugar 

 in the blood rapidly decreases; apparently, therefore, the activity of the 

 chromaffin tissue is discontinued if its connection with central projection- 

 fields is interrupted. The number of experiments is not at all great, as the 

 operative attack is difficult. It seems to me, however, noteworthy that 

 indications are wanting that after this attack, which also deprives the insular 

 apparatus of its central innervation, disturbances in the insular apparatus 

 occur during the short time that the animals survive the attack. I would 

 not at all state that the activity of the insular apparatus is not regulated by 

 the central nervous system; it seems, however, as though this influence were 

 very much slighter than is true in the case of the chromaffin system ; the in- 

 sular apparatus seems better able to continue its activity for some time even 

 after interruption of its connecting paths. That the production of the assimi- 

 latory hormone is accessible to few nerve influences seems purposeful; such 

 ductless glands always seem to work with a certain surplus; while the giving 

 off of the dissimilatory hormone must be very finely graduated in order to do 

 justice to the rapidly changing demands; this is only possible, however, if 

 the central nervous system governs the function of the ductless gland furnish- 

 ing them. 



That the activity of the thyroid gland is dependent on the central nervous 

 system may be concluded from the older literature. How otherwise can 



