144 THE VENOMS OF CERTAIN THANATOPHIDEJ1. 



Liquids in general variously modify the shape of the red blood-disks, but no 

 liquid or reagent tried in control experiments produces the effects described 

 above. 



Watery solutions of dried venom did not exhibit the immediate influence upon 

 the red blood corpuscles as well as the fresh venom, although the corpuscles very 

 promptly became spheroidal as they do from most watery liquids ; but did not lose 

 the coloring matter as when exposed to pure water without venom. 



The blood of birds, upon being mixed with venom, does not show the above 

 described changes in as striking a manner as mammalian blood. The nuclei of 

 the oval corpuscles of the pigeon appear, however, to undergo a rapid necrotic 

 change which finally gives rise to a granular albuminoid material to be seen 

 floating in large quantities between the corpuscles. 



A number of experiments were made to study the changes in the corpuscles of 

 the living animal. Fresh venom or solutions of dry Crotalus venom were injected 

 hypodermatically, and then the blood taken at intervals from the local lesion as 

 well as from the general circulating fluid and examined under the microscope. 



The blood taken from local lesions presented quite often alterations in the cor- 

 puscles similar to those observed in a direct mixture of blood and venom under the 

 microscope, as described above. It was not possible, however, to trace all the 

 modifications of the red blood corpuscles in specimens of the circulating blood ; 

 only one change being constant, viz., the spheroidal transformation of the blood 

 disks. The red blood corpuscle retained the acquired spherical shape after the 

 death of the animal. 1 



All the experiments made in order to study the ultimate changes in the blood- 

 corpuscles gave nearly similar results varying slightly in degree with the quantity 

 of the venom and the animal employed. The record of one observation will suffice 



for all. 



Experiment. — Young cat. Injected at 2 p. M. 3 m. m. fresh Crotalus venom in 



left thigh. Hair of part being previously clipped away. 



2 minutes later. Animal well. Blood microscopically examined. Local lesion ; 

 blood-disks assuming spherical-shape. Blood from auricular artery showed no 

 changes in the blood-disks. 



5 minutes later. Animal well. Local lesion ; blood-disks all spherical showing 

 also gelatinoid behavior and ductility on pressure. Auricular artery, blood-disks 

 normal. 



8 minutes later. Animal restless. Local lesion shows only spherical shape of 

 red blood-disks. Auricular artery also shows partial change of red blood-disks to 

 spherical shape. 



12 minutes later. Animal ill. Blood of local lesion as well as blood taken from 

 jugular vein shows same changes as when last examined. 



1 Errors in distinguishing the spheroidal shape of the red blood-corpuscles from the round shape 

 which the normal disk-like corpuscles exhibit when viewed in a certain position are easily eliminated 

 when the blood is brought into current by gentle pressure upon the cover-glass, or by inclining the 

 stage of the microscope. The disks assuming spheroidal shape are decidedly reduced in diameter 

 and appear smaller. 



