CHAPTER XVIIL. 
HISTOLOGICAL CHANGES PRODUCED BY SNAKE VENOM 
ON VARIOUS ORGANS AND. TISSUES. 
Before presenting the facts derived from the elaborate and extensive studies 
of various investigators concerning the histological alterations produced by 
snake venom, a general review of the nature of these changes may be per- 
mitted at this place. 
As we shall presently see, the histological changes, which were demon- 
strable with the practicable methods of our past and present histological 
status, fall into two great groups. ‘The first group is the fatty degeneration of 
the protoplasma of the diverse kinds of cells, and the other comprises the 
changes designated necrosis. The question quickly arises whether both 
are the action of the same principles or the actions of specific agents for each 
group of alteration. In view of the recent development in the biochemical 
investigations of the active principles contained in snake venom and other 
similar cellular toxins, it appears that the latter hypothesis conforms to the 
observed facts. The lipolytic properties of snake venom— especially the libera- 
tion of fatty acids from phosphorized and non-phosphorized fats by certain 
ferment-like principles of venom — render it probable that fatty degeneration 
is the result of the cytolysis of such agents. It is partly due to the Ehrlich- 
Kyes phenomenon (or formation of lecithids and liberation of free fatty acids) 
and to the Neuberg-Rosenberg phenomenon (or the splitting of neutral fats), 
both being liable to take place in media as rich in lecithin and fats as the cell 
protoplasma. Considering the potency which a minute quantity of venom 
circulating in the venomized body possesses, it is again reasonable that in the 
production of fatty degeneration lecithin-splitting plays the foremost part. 
The necrotic changes I consider due to the specific phenomena peculiar to 
each group of somatic as well as nervous tissues, and brought about by the 
action of specific cytolysins in the sense of Flexner and Noguchi, namely: 
there exists between the cells and the active principles a special affinity, if not 
specific. ‘The relation between fatty degeneration and the necrotic altera- 
tions of these cells is not quite clear, inasmuch as various fatty and lipoid 
substances display marked destructive effects on various cellular elements. 
It may be true, at least in part, that the necrotic processes are caused second- 
arily by the primary fatty degeneration. On the other hand, there are many 
evidences that point in the opposite direction. Fatty degeneration may be 
entirely absent from the cells showing marked disorganization of their con- 
stituents. Equally we may assume that fatty degeneration may be produced 
secondarily by the cessation of the normal oxidating function of the cells, 
through specific toxins of venom. In deciding this point the results which I 
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