OF WASHINGTON. 85 



was found in quite large series in the ovaries of Coursetia (?) 

 mexicana, a rare leguminous plant collected in the Alamos 

 Mountains, Mexico, by Dr. Edward Palmer. 



Dr. Marx then read a paper of which he has furnished the 

 following abstract : 



ON THE EFFECT OF THE POISON OF LATHRODECTUS 



MACTANS WALCK. UPON WARM-BLOODED 



ANIMALS. 



BY GEO. MARX, M. D. 



In the early part of last October I came accidentally in pos 

 session of quite a number of living specimens of this spider, 

 so notorious on account of its supposed poisonous properties, 

 and I concluded to make some experiments as to the effect of 

 its poison on warm-blooded animals, in order to settle defi 

 nitely, if possible, the question whether the bite of this 

 spider may be fatal to man. This question, which some time 

 ago had agitated scientists of many countries, was raised 

 again by the recent publication of a case of alleged poisoning 

 of a man in North Carolina with fatal results within less than 

 twelve hours.* 



As objects for the experiments of inoculations of the virus 

 the following animals were selected : a rabbit, four Guinea 

 pigs and a mouse, all healthy and well fed, which were 

 kindly furnished by the Bureau of Animal Industry of the 

 Department of Agriculture. The spiders, nearly all mature 

 females, were fed copiously with flies and some Carabid 

 beetles, which were devoured with great relish. 



In dissecting the spiders the mandibular (poison) glands 

 were found to be extremely small in comparison to those of 

 other spiders. The walls of these glands being composed of 

 both muscular (striated) and fibrinous bundles, are so thick 

 that only a very narrow channel is left as a receptacle for the 

 poison, and which would hold only about y-ioooth part of one 

 cubic millimeter. As the spider possesses two such glands, 

 which both are used always in biting, the quantity of poison 

 which might be introduced into the body of the victim by the 

 bite would therefore not be more than 14-1000, or about 

 i~75th of a cubic m.m., equal in bulk to the i-5oooth part of 

 a drop of distilled water. 



*See Insect Life, I, pp. 204-211 (i 



