EFFECTS OF VENOM TREATMENT 243 



lethargy, paralysis, unconsciousness, and respiratory con- 

 vulsions. The blood coagulates firmly after death. All 

 observers agree that the venom of certain sea-snakes is 

 of peculiar virulence. Major Leonard Rogers, who has 

 worked a good deal with the venom of certain sea-snakes, 

 emphasizes the facts that this venom is neurotoxic like 

 cobra-venom, but is many times more potent, that there 

 is a considerable latent period before any symptoms are 

 manifested, and that there is no appreciable action on the 

 blood. 



(c) Effects of the Venom of Rattlesnake (Crotalince). 

 The symptoms and sequelae in a case ,of bite by a 

 rattlesnake are in many ways similar to those caused by 

 Viperine venom. The general symptoms are rapid in 

 onset, and are marked by syncope a,nd alarming collapse, 

 which may end in death or may be followed by very 

 rapid recovery. Locally there is severe pain and extensive 

 swelling and extravasation, which may go on to spreading 

 gangrene, and a lingering death from septicaemia. The 

 sudden and alarming prostration appears to be due to 

 specific toxins acting directly on the vaso-motor system 

 and heart, which are more abundant in rattlesnake-venom 

 than in other venoms. 



The action of the venom of certain other notorious 

 snakes will be referred to in the section dealing with 

 the distribution of Thanatophidia. For the present this 

 subject may be left with a repetition of the caution that 

 a bite even an untreated bite from a snake known to 

 belong to a powerfully venomous species is not by any 

 means necessarily fatal to man. A bite from such a snake 

 is dangerous only if the animal be in a good condition, 

 with its glands full of venom, and if it take firm hold with 

 its teeth, so as to bite home and inject a lethal charge 

 of the poison. Conversely, these considerations suggest 

 that it must be unsafe to make generalizations as to the 

 virulence of an unstudied species from the effects of a 

 single chance bite ; trustworthy information is to be 

 gained chiefly by a series of experiments with known 

 quantities of extracted venom. 



