114 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



In still other series of experiments the venom was directly injected into the 

 pectoral muscle of pigeons, i drop of fresh crotalus venom being used. The 

 time intervening between injection and death was from 15 to 25 minutes. 

 The muscle becomes peculiarly soft and swollen, with extensive extravasation 

 of blood, which makes it very dark. The coagulability was more or less 

 reduced or completely lost. Where death followed injection instantaneously, 

 the blood was firmly coagulated. Haemorrhages below serous membranes — 

 subpleural, subperitoneal, and subpericardial — are the most frequent and 

 most pronounced. In cases where death does not occur the local tissue may 

 form slough, but a dry atrophy, such as was observed by Mitchell and Reichert 

 in a pigeon, is very rarely caused. I was able to confirm most of the experi- 

 ments of these authors. 



Among the mammals, the rabbit, guinea-pig, cat, dog, rat, mouse, horse, 

 and goat are all susceptible in varying degrees. 



A rabbit struck by a rattlesnake may die in one minute. In such case no 

 lesions in the organs are visible. The blood coagulates firmly or extensive 

 thrombosis exists in the large veins and pulmonary artery. In another in- 

 stance Mitchell describes a case where a rabbit was struck by an exhausted 

 snake, and died 3 days afterwards. In this case bloody feces and albuminuria 

 were observed. A most extensive dissemination of ecchymoses throughout 

 the mucous membranes and nervous system, and accumulation of consider- 

 able amounts of bloody serum in the cerebral ventricles and pericardium, 

 were observed. The kidneys were also enlarged and were soaked with dark 

 fluid blood. In cases of death, which occurs in 15 minutes to several hours, 

 prostration, a loss of motor power, jerking respiration, general twitching, 

 feebleness of the heart and pulse and often violent convulsions before death 

 are the chief general symptoms, while the bitten muscle becomes swollen, 

 tender, and soaked with the haemorrhages. Coagulability may be absent 

 from the blood of these animals. Ecchymoses are very numerous through- 

 out various internal organs and mucous and subserous surfaces. The guinea- 

 pig, rat, cat, and mouse are affected in similar manner as the rabbit. The 

 horse is also highly sensitive to the action of crotalus venom, as was shown 

 by McFarland in an attempt to immunize it against this venom. The goat 

 appears more resistant to this venom. 



Some experiments made by Mitchell on dogs are extremely instructive. 

 At first the rattlesnake failed to fully insert its fangs into the skin of the dog 

 brought before it, the bite being imperfect or an entire failure. Finally the 

 snake was seized by the neck and forced to bite the dog. Even with this 

 plan many dogs, while suffering general and local disturbances, escaped death. 

 In some cases death ensued several hours after the bite. The usual crotalus- 

 poisoning symptoms l were seen during life, and the autopsies revealed the 

 dark, infiltrated local lesions, but seldom any ecchymoses in internal organs. 

 Serous cavities contained laked fluid in varying quantities. The coagulabil- 



*.It is very interesting to notice that after the bite the dogs showed a great thirst and drank water inces- 

 santly. This symptom is not uncommon in the Bothrops poisoning in man. 



