480 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



These snakes, however, classed morphologically iamongst 

 the colubrine snakes, resemble the vipers as regards the 

 nature and action of their poison. Weir Mitchell, as the 

 resnlt of experiments with crotalas venom, upholds this 

 opinion. Cunningham, however, working with the poison 

 of daboia, or Russell's viper, puts forward the opinion that 

 rapid death from the bite of this snake is due to its direct 

 action on the central nervous system. 



From the fact that Martin nsed the venom of snakes 

 which are not true vipers, and whose poison, he admits, is 

 probably related in physiological action to that of the 

 cobra and also the viper, Captain Lamb, I. M.S., and the 

 writer undertook some experiments with the venom of a 

 true viper, viz., daboia, or Russell's viper. As a result 

 of these observations it would appear that when death 

 rapidly follows an injection of viper venom, made 

 either subcutaneously or directly into the blood stream 

 (the fang of a snake frequently enters a large vein when 

 a person is bitten), more or less extensive intravascular 

 clotting is always found on careful examination 

 immediately after death. Further, it would appear that 

 even when a dose of poison, which just fails to cause this 

 clotting, is injected, very slight symptoms, or none at all, 

 appear. In certain cases, however, where the venom has 

 been introduced subcutaneously in a small dose which fails 

 to cause coagulation, serious symptoms of chronic intoxica- 

 tion, or even death, may arise lgter. 



The question evidently resolves itself into the considera- 

 tion as to whether the intravascular clohting, which is 

 present in all oases, can explain the symptoms observed 

 and the rapidly fatal issue. 



The objective symptoms following coagulation in the 

 pulmonary arteries, or their main branches, are well 

 known, and there can be no doubt that the extensive intra- 



