22 SNAKE-POISON AND ITS ACTION. 



motor force supplied by the splanchnicus, keeping 

 them in the normal state of contraction when intact 

 and having its centre in the medulla oblongata. When 

 this large vaso-motor nerve is cut in animals anywhere 

 in its course, the veins of the abdomen become distended 

 enormously. The animal is, so tp say, bled into its own 

 belly. 



By a series of most interesting experiments 

 Feoktistow has shown conclusively that snake-poison 

 has the same effect on the abdominal circulation as 

 section ot the splanchnicus. Even slight intravenous 

 injections of the poison produced quickly a high degree 

 of paresis of the nerve and a corresponding engorgement 

 of the veins of the abdomen, whilst after lethal doses, 

 the paresis culminated in a few minutes in complete 

 paralysis, followed by rapid collapse, excessive weak- 

 ness of the bloodless heart, and death from paralysis 

 of the latter and anaemia of the nerve-centres. One 

 experiment deserves special record, as it also shows 

 the untenability of the blood-poison theory. 



The whole vascular system of an animal poisoned 

 by intravenous injection was thoroughly washed out 

 with the warm defibrinised blood of four animals of 

 the same species, the blood being infused into an 

 external jugular vein and allowed to flow out of a 

 crural artery. Although blood exceeding its normal 

 quantity was left in the animal, when the vessels 

 named were closed, the nerve affection remained 

 unchanged. The blood pressure raised during the 

 infusion sank at once again to zero, when it ceased, 



