THE POISON OF THE COMMON GARDEN SPIDER. 173 



toxin nature of any substance. Owing to the scarcity of material 

 the immunizing experiments were somewhat delayed; they will, 

 however, be dealt with in detail at the proper time. Nevertheless 

 I can announce that shortly before the conclusion of this work we 

 succeeded, by means of a short immunization of guinea-pigs l with 

 garden-spider poison, to produce a high-grade antitoxic serum, of 

 which 0.0025 cc. sufficed to fully protect 0.05 cc. rabbit blood against 

 a complete solvent dose. This proves the toxin nature of arachnolysin. 

 In conclusion I should like to refer to the relations which arachnoly- 

 sin bears to what we know about spider poisons in general. In doing 

 so I shall follow Robert, 2 who made the fundamental studies in the 

 toxicology of animal and vegetable poisons, and to whom we owe 

 most of our knowledge concerning spider poisons. In addition to 

 the true secretion of the poison gland, Robert distinguishes "a toxal- 

 bumin which permeates the entire body of the spider, even the legs 

 and eggs, but which bears no necessary relation to the poison gland." 

 In some species of spiders this substance mixes with the gland poison. 

 According to Robert, the more toxalbumin gets into the wound, the 

 stronger are the constitutional symptoms; the more true gland poison, 

 the stronger the local changes. The latter is especially the case in the 

 lathrodectes species (malmignatte, karakurte) whose sting produces 

 most fearful general symptoms, even being able to kill human beings. 

 In these the gland secretion becomes dangerous only when mixed 

 with toxalbumin derived from the body. In contrast to this, the 

 sting of the garden spider produces only local symptoms of irritation, 

 although the spider's body contains a toxalbumin whose action is 

 analogous to the preceding; but this substance does not become 

 mixed with the gland secretion. This being the case, it is very likely 

 that the haemolysin described by us is identical with the toxalbumin 

 already known to Robert; for we also obtained it from the body 

 substance of the garden spider, and found its properties to be those 

 of the toxin. 



ADDITION ON REVISION. Since sending in the manuscript of this study I 

 have learned of a monograph by Robert (Beitrage zur Kenntniss der Giftspinnen, 

 Stuttgart, 1901) which has just appeared. In this Robert also reports on the 

 h.Tmolytic action of the poison of Rarakurtes and of garden spiders. He states 



1 Hence although guinea-pig blood is insensitive to arachnolysin, appropriate 

 receptors capable of binding the poison must be present in the guinea-pig organism 

 outside of the blood. 



'Robert, Lehrbuch der Intoxicationen, Stuttgart, 1893, p. 329. 



