130 THE VENOM OF HELODERMA. 



below normal. This ulceration was independent of the state of dying, inas- 

 much as animals killed at a much earlier period showed the same change, but 

 the changes were usually more marked in direct proportion to the degree of 

 intoxication manifested by the animal. 



THE TYPICAL ULCER. 



The typical ulcer, usually accompanied by hemorrhage, was, on exposure 

 of the peritoneal surface of the stomach, generally seen as a purplish-red cir- 

 cumscribed patch. If ulcers were unaccompanied by hemorrhage and this 

 was by no means rare they appeared as rounded grayish points. On opening 

 the stomach, hemorrhage was usually seen; after removing the blood the char- 

 acteristic ulcer appeared, varying from 1 to 8 mm. in diameter. Occasionally, 

 by confluence, they would involve as much as 0.5 square inch of the gastric 

 mucosa. They were always found in the cardia and fundus, and were never 

 observed in the pyloric fifth of the stomach. They are found more frequently 

 at the greater curvature than at the lesser, but were by no means excluded from 

 the latter. Of interest is their occurrence in discrete clusters most frequently 

 on the anterior cardiof undal region or near the center of the stomach around 

 the greater curvature. This arrangement might be explained on the ground 

 that each territory involved was nourished by a certain blood-vessel and its 

 branches. We endeavored, therefore, to ascertain, by holding the entire mu- 

 cosa up to the light, what relation these ulcers held to the distribution of the 

 vessels, and found a certain proportion of the clusters bearing some relation to 

 the vessels. 



The ulcers, when typical, are round, sharply circumscribed, with sloping 

 edges resembling a peptic ulcer in the stomach of man, with or without a hem- 

 orrhagic base. Frequently the ulceration reaches down to the muscularis, and 

 the ulcer then has a translucent appearance when viewed from the peritoneal 

 surface and has usually a number of hemorrhagic erosions combined with it. 

 These erosions occur so frequently and are seen so constantly, especially when 

 an animal is killed soon after injection, before a definite ulcer has had a chance 

 to develop, that in all probability the hemorrhagic erosion represents an early 

 stage of these ulcers. Indeed, all transitions can be found, from hemorrhagic 

 erosion to distinct, large, and well-defined ulcers. These ulcers bear a striking 

 resemblance to the ulcers described by Bolton,* and, to judge from his descrip- 

 tion, the appearance of both kinds is identical. The fact that Bolton's lesions 

 were acute also favors this view of the identity of both varieties ; but we do not 

 know whether the condition of marked intoxication, so important in the pro- 

 duction of venom ulcers, was equally present in his animals, nor whether the 

 anatomical position of the ulcers was the same in both cases. Both of these 

 ulcers differed from those produced by Rosenau and Anderson in that the latter 

 were confined to the pyloric region. Furthermore, as will be shown later, 

 hemorrhage was not the primary factor in the ulcers produced by the injec- 

 tion of venom. 



"Proc. Roy. Soc., 1905-1906, series B, 77, pp. 425, 428; series B, 79, 1909. 



