CH. XXIT.] PATHOLOGICAL CONDITIONS 311 



box, covered with a glass plate made air-tight with vaseline. There 

 are always two openings to such a box, one to allow the vessels and 

 nerves to enter (leakage of air around these is prevented by packing 

 with cotton-wool soaked in vaseline) ; the other opening is filled up 

 with a piece of glass tubing which is connected by an india-rubber 

 tube to the recording apparatus (see fig. 272). The most delicate of 



FIG. 272. Apparatus for obtaining splenic curves, s, Spleen in oncorneter o, which is made of gutta- 

 percha, and covered with a glass plate (G.P.) luted on with vaseline. M is the splenic mesentery 

 containing vessels and nerves ; this passes through a slit in the base of the oncometer which is 

 made air-tight with vaseline. The oncometer is connected to the flexible bellows (B) by the india- 

 rubber tube (R), the side tube (T) being closed during an experiment by a piece of glass rod. The 

 recording lever (L) writes on a revolving drum. 



the volume recorders is the bellows-recorder of Brodie or the piston 

 recorder of Hiirthle. 



Of all the oncometers, I am inclined to believe that the intestinal 

 oncometer is the most instructive, because the coil of intestine under 

 observation gives a truer record of what is occurring in that important 

 area called the splanchnic area, than any other abdominal organ. 



Pathological Conditions. 



The vaso-rnotor nervous system is influenced to some extent by 

 conditions of the cerebrum, some emotions, such as fear, causing 

 pallor (vaso-constriction), and others causing blushing (vaso- 

 dilatation). 



It is almost impossible to over-estimate the importance of the 

 study of vaso-motor phenomena as a means of explaining certain 

 pathological conditions; our knowledge of the processes concerned 

 in inflammation is a case in point. 



Disorders of the vessels due to vaso-motor disturbances are 

 generally called angio-neuroses. Of these we may mention the 

 following : 



Tache cerebrate is duo to abnormal sensitiveness of the vascular 



