70 THE VENOM OF HELODEEMA. 



connective-tissue cells between the tubules and about the glomeruli. The 

 epithelium of the tubules was swollen and in many places obliterated their 

 liunen. The nuclei of some of these cells showed karyolysis and in some 

 tubules nuclei were seen lying free in the lumen. The glomeruli of this kid- 

 ney showed no distinct signs of involvement. One other kidney removed from 

 an animal which had received 67.5 mg. of venom during a period of 3 months 

 showed a slight increase of connective-tissue cells between the tubules. The 

 kidneys of the other animals examined appeared normal. 



All the hearts examined were normal, except one which showed a slight 

 increase of connective tissue between the muscle-fibers and also a marked 

 degree of vacuolization in the muscle-fibers over a rather small area. Else- 

 where the muscle-fibers of this heart were normal. This animal, in which also 

 a connective-tissue overgrowth in the kidney was found, had received 67.5 mg. 

 of venom during a period of 3 months. 



The lungs of several of the rabbits showed pneumonic areas. In these 

 areas the capillaries were congested and the alveoli contained desquamated 

 epithelium, polymorphonuclear leucocytes, and considerable granular detritus. 

 In the lungs showing this condition the large vessels were dilated with blood. 

 It is probable that this pneumonic condition represents simply a terminal 

 infection and can not be attributed directly to the influence of the venom. 



The bone-marrow and spleen of animals that had received a nmnber of 

 injections of venom showed more constant changes than did the other organs. 

 In bone-marrow, which showed no gross change, it was generally noted that the 

 giant cells were increased in number (in four or five cases) ; the polymorphonu- 

 clear leucocytes seemed to be increased in number, while the erythroblasts 

 showed a relative decrease. The histological picture suggests at least that 

 there was an effort to regenerate leucocytes or to produce a leucocytosis, and 

 this latter explanation is in agreement with the blood-picture noted in animals 

 which received repeated injections of heloderma venom. 



The spleens of the rabbits which had received several injections of venom 

 showed several types of changes, one or more of which appeared in the spleen 

 of every animal examined. Most commonly we noted a change in the mal- 

 pighian corpuscles. These appeared smaller than normal and the cells forming 

 these bodies were less densely packed about the small vessels; in short, the 

 malpighian corpuscles were less prominent than normal. Almost as regular as 

 this change in the malpighian corpuscles was the proliferation of the endothelial 

 cells in the splenic pulp. This proliferation of the endothelial elements of the 

 splenic pulp was at no place very marked, but appeared diffusely throughout 

 the spleen. In a few cases we noted the splenic pulp to be less dense and cellu- 

 lar, and as a result of this thinning of the splenic pulp the connective-tissue 

 framework — especially the finer trabeculse — became more prominent. The 

 cellular elements of the spleen pulp did not show any marked changes; no one 

 type of cell appeared to be unduly increased or diminished. 



Thus we see that in the liver, kidney, and heart the venom does not pro- 

 duce any typical histological changes, but, when injected repeatedly over a 



