SPIDER VENOM. 235 



ROBERT was able to show that there was no specific poison in 

 those species of spiders most accused of containing it, and in 

 particular the tarantulas. In fact, real poisons were only found 

 in two genera viz., Lathrodectes and Aranea diademata (Epeira 

 diadema, the garden spider). 



The Lathrodectes are distributed over the whole globe. The 

 most important species are those of Italy (L. tredecimguttatus, 

 Malmignatte) and of South Russia (L. erebus, Karakurte), with 

 those of New Zealand (L. scelio and Hasseltii, Katipo) and of 

 South America (L. mactans). As far back as 1765 YALMONT 

 DE BOMBAKE gave a description of the poisonous properties of 

 the malmignatte, and since then they have frequently been 

 studied. Experiments on animals have also been made. 



A whole series of reports has been collected by KOBEET with 

 regard to the Russian spider, and from these it appears that the 

 Lathrodectes not only inflicts great injury upon cattle, horses, 

 and camels, but even kills men. The effects are very severe : 

 violent pains, priapism, sleeplessness, great prostration, cold 

 sweating, fever, and dyspnoea. The general symptoms closely 

 resemble those caused by poisoning with bacterial toxines. 

 No striking alterations can be observed in the vicinity of 

 the bite. Convalescence is very tedious, but fatal cases are 

 very rare. 



ROBERT has made experiments on his own account with 

 aqueous extracts of these Crimean karakurtes, some of the 

 extracts being prepared from the fresh animals, and others from 

 those that had been partially dried. 



These extracts were found to be very poisonous, producing 

 exactly the same results as those observed in men bitten by the 

 spider. The intravenous injection of a few mgrms. per kilo, of 

 organic substance into dogs and cats produced dyspnoea, convul- 

 sions, and paralysis of the respiratory system and heart, speedily 

 ending in death. Rabbits, rats, and birds were also susceptible 

 to the poison, but the hedgehog offered somewhat more resistance. 

 Frogs and leeches could also be poisoned. There was practically 

 no difference in the action of extracts obtained from the front 

 and from the back portion of the spider. New-born spiders 

 were more venomous than full-grown ones, and even the eggs 

 were poisonous. The poison had an injurious effect upon the 

 isolated heart of the frog, even in the proportion of 1 : 100,000. 



ROBERT also succeeded in producing immunity by cautiously 

 inoculating experimental animals, so that karakurte poison 

 appears to be a true toxine. Boiling renders the poison com- 

 pletely inactive, and alcohol has the same effect. Introduced 



