INTRODUCTION. IS 



of an almost incredible complexity. If, on the other hand, we should reject 

 such a conclusion we must be aware that much of the evidence as to the differ- 

 ence between hemolysins and neurotoxins of a single venom is of a similar char- 

 acter. At present we can only point out these apparent contradictions; it 

 remains for further studies to solve these problems. 



Provisionally we may suggest that perhaps certain proteid constituents of 

 the venom are responsible for some of these apparent discrepancies ; it may be 

 that these proteids are able to increase or diminish certain functions of the 

 poisonous principle and that the effects of heat and certain chemicals concern 

 rather these secondary substances than the poison proper. As far as immuni- 

 zation is concerned, these proteids may perhaps, to use the terminology of 

 Ehrlich, supply a multiplicity of haptophore groups, all linked to a uniform 

 toxophore group, which latter would represent the poisons isolated by Faust. 

 Future investigation will also have to analyze the mechanism through which 

 the neurotoxic effect is produced. Do we have to assume that the structure of 

 the various body-cells is in the main similar, as far as the conditions of perme- 

 ability of the outer protoplasmic layer are concerned? Are the neurotoxic and 

 hemolytic effects produced in a similar manner? A number of observations 

 point to the importance of a change in cell permeability as one of the factors 

 through which the poison exerts its injurious effect, as the significant action of 

 CaCl2 and of sugar on the hemolytic action of venom already discussed indi- 

 cates. Furthermore, the observations of Noguchi, that the later stages of the 

 developing ova of Fundulus were more resistant to the action of venom than 

 the earlier stages, are in agreement with my observation in regard to the action 

 of neutral red on Fundulus eggs. In this case I also found the later stages 

 more resistant than the earlier ones, and I could furthermore show that this 

 difference in resistance depended upon a difference in the permeability of the 

 egg-membrane for neutral red. (Elizabeth Cooke and Leo Loeb, Ueber d. 

 Giftigkeit. einiger Farbstoffe fuer die Eier von Asterias und von Fundulus^ 

 Biochem. Zeitschrift, Bd. 20, 1909.) 



That a certain venom destroys various kinds of cells through a similar 

 mechanism is perhaps indicated in the observations of Flexner and Noguchi, 

 who found that cobra venom which exerts a strongly neurotoxic action has 

 also a very marked lytic effect upon other kinds of cells. This lytic action of 

 cobra venom surpasses that of certain Viperidse in correspondence with the 

 stronger neurotoxic action which cobra venom exerts in the living body. On 

 the other hand, the dissolving action of certain venoms on muscle seems to be 

 due to a different mechanism, and accordingly we find in this case crotalus 

 venom exerting a more powerful influence than cobra venom. 



It is to be hoped that future investigations will definitely answer these 

 questions and will thus deepen our understanding of the conditions which 

 determine the function and death of the various cells of the animal body. 



