CHAPTER XXVIII. 



EFFECTS OF SNAKE VENOM UPON THE BLOOD OF COLD- 

 BLOODED ANIMALS, AND UPON THE NERVE CELLS, 

 NERVE FIBERS, OVA, AND SPERMATOZOA. 



Fontana, 1 as early as 1787, performed experiments on the effects of the 

 venom of viper on vipers, two innocuous snakes, one salamander, turtles, 

 and leeches, and found that none of these cold-blooded animals die of viper 

 poisoning. On the other hand, he found certain fish and frogs to be sus- 

 ceptible to the viper's venom, death following the bite after a much longer 

 time than in the cases of warm-blooded animals. 



In 1860-1861 S. Weir Mitchell 2 made a careful study of the effects of 

 crotalus venom upon frogs, and observed two kinds of venom poisoning — an 

 acute or rapid and a chronic or slow poisoning. He pointed out the rela- 

 tively greater resistance of frogs to the venom. 



For physiological and pharmacological experiments with various kinds of 

 venom on isolated organs, the frog has been nearly always employed by in- 

 vestigators, and it would be superfluous to give any further description of 

 the effects which venom produces on this animal. 



Brunton and Fayrer 3 also made a few experiments on cold-blooded animals. 

 Two fishes, Ophiocephalus marulius and a carp, succumbed to the cobra 

 venom. Cobra venom seems to destroy the irritability of snails. 



According to Rogers, the venom of marine snakes, as compared with that 

 of land snakes, acts more powerfully upon marine animals than upon the 

 warm-blooded animals, although the absolute susceptibility of these two 

 orders of animals to the first venom is greater in the case of the warm-blooded 

 animals. 



A more systematic study of the effects of snake venom on cold-blooded 

 animals has been recently made by Noguchi. The results obtained by him 

 were first issued as Publication No. 12 of the Carnegie Institution of Wash- 

 ington, and are quoted in the following pages (271-280). 



1 Fontana. Abhandlung iiber das Viperngift. 1787, Berlin. 



2 Weir Mitchell. Physiology and toxicology of the venom of the rattlesnake. Smithsonian Contr. 



to Knowledge, 1861, Washington, 

 a Brunton and Fayrer. On the nature and physiological action of the poison of Naja tripudians and 

 other Indian venomous snakes. Proc^ Roy. Soc, 1874, 68. 



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