PATHOLOGY. 143 



Microscopical Changes in the Various Tissues of the Body from the Effects of the 



Venom of Crotalus. 



Effects of Fresh Venom upon the Blood Corpuscles. — A series of experiments 

 were made to study the direct as well as the remote effects of the venom upon the 

 blood corpuscles. The result of these observations was the discovery of some 

 changes which have not been heretofore fully described. 



A drop of blood from man or any mammal treated with a minute quantity of 

 fresh venom, presented the following appearances under the microscope : Upon 

 the white blood corpuscles, the venom did not appear to have any other effect than 

 to stop the amoeboid motion, which in presence of venom could not be kept up, 

 even by the use of the warm stage. The cells appeared somewhat larger than 

 usual and also more granular. The red blood corpuscles appeared unchanged 

 when observed, but for a moment, and superficially, yet prolonged and careful 

 study revealed very remarkable alterations. The alterations in the red blood cor- 

 puscles are essentially these : — 



The blood disks lose their biconcavity and assume a spherical form, but without 

 parting with their coloring matter. They exhibit also great adhesiveness, arrang- 

 ing themselves into various sized and shaped aggregations. The corpuscles com- 

 prising these groups sometimes appear to fuse so that their outlines cannot be 

 determined, even by high amplification. In addition the corpuscles seem to soften 

 and acquire a peculiar ductility and capacity to be stretched without fracture. By 

 inclining the stage of the microscope, or making gentle pressure upon the cover- 

 glass, allowing thereby the liquid to flow, the red blood corpuscles may be seen to 

 elongate themselves into spindle-shaped or even into fine thread-like bodies. 

 (Figs. 1 and 2, Plate III., and Plate IV.) Such masses of corpuscles appear to act 

 like colloid material. 



One drop of human blood was mingled with one of fresh snake venom by the 

 application of the cover-glass. The three fields photographed were found in the 

 zones of contact between the blood and venom ; they occurred within a small area — 

 almost adjacent. Fields 1, 2, and 3, Plate IV., were photographed respectively 

 within 15, 30, and 40 minutes after the first application of the venom to the 

 blood. As the masses of corpuscles were slowly changing form and position, the 

 exposure was, necessarily, but for a part of a second. The lens employed was 

 Spencer ^ immersion, giving 400 diam. with the low power eye-piece. 



This remarkable condition seems, however, to be only temporary, and in fact 

 often escapes observation. After a short time, which in about 100 observations 

 was found to vary from a few seconds to a quarter of an hour, the apparently 

 homogeneous blood-cell masses break up anew into individual corpuscles, which 

 then continue isolated or in bead-like rows, but remain spheroidal, *. e., do not 

 regain their biconeal shape. 



Those corpuscles which arrange themselves in rows present an appearance strik- 

 ingly different from the ordinary rouleaux arrangement of normal blood-disks, an 

 appearance which may better be designated as "beaded," because the corpuscles 

 are here spheroidal and not disk-like. 



