§ 652.] POISONOUS SPIDERS AND INSECTS. 499 
dectes lugubris, common in South Russia, and attaining a length of 2 cm. 
The Kara-Kurt poison is not only to be found in special glands, but 
is also diffused through the body. According to Robert, who has inves¬ 
tigated this poison, it is a generic type of the poison of spiders ; the 
active principle is neither a glucoside, an acid, nor an alkaloid. It 
does not dialyse, and drying destroys its activity ; it has the characters 
of a toxalbumin, and has much similarity to the action of ricin and 
abrin. The Kara-Kurt poison dissolves the colouring-matter of the red 
blood corpuscles, even with a dilution of 1 : 127,000 ; it has a paralysing 
effect on the heart, either due to action on the motor ganglia, or, possibly 
a direct action on the muscle itself. The blood-pressure sinks, the walls 
of the smallest arteries and capillaries become so changed as to allow 
the transudation of blood and serum, producing punctiform haemorrhages 
and oedema. This is best seen in the lungs. The poison also has a 
paralysing action on the central nervous system, but it is not clear 
whether this action is primary, or whether it depends on the circulation 
troubles. 
The fatal dose of the poison, injected subcutaneously or intravenously, 
is extremely small. Cats are killed by quantities equal to 0-2 to 0-35 
mgrm. per kilo, body weight. Repeated injections of non-fatal doses 
confer immunity. 
The Epeira diadema, the ordinary cross-spider, so called from cross¬ 
shaped whitish spots on the abdomen, is common in Europe generally. 
Robert has investigated the poison it possesses, and finds it of the same 
class as that of the Kara-Kurt, but slightly weaker ; he states, however, 
that in a single female cross-spider there is enough poison to kill a 
thousand cats. 
Lycosa tarantula, a spider from 3 to 3-5 cm. long, occurs in Italy, 
Spain, and Portugal. Zangrilli has observed several cases of tarantula 
bite ; soon after the occurrence the part bitten is anaesthetic, after a few 
hours there are convulsive shiverings of the legs, cramps of the muscles, 
inability to stand, spasm of the pharyngeal muscles, quickening of the 
pulse, and a three days’ fever, with vomiting of yellow bilious matter ; 
recovery follows after copious perspiration. In one case there was tetanus, 
and death on the fourth day. The extraordinary effects attributed to 
the bite of the tarantula, called tarantism in the Middle Ages, are well 
detailed by Hecker ; 1 this excitement was partly hysterical and partly 
delirious, and has not been observed in modern times. 
Dax has described the effects of the bite of the L. malmignatus ; it 
occasioned headache, muscular weakness, pain in the back, cramps, and 
dyspnoea ; the symptoms disappeared after several days. 
§ 652. The Katipo is a small poisonous spider confined to New 
1 The Epidemics of the Middle Ages, by J. F. C. Hecker, translated by B. G. 
Babington, M.D., F.R.S. (“The Dancing Mania,” chap, ii., etc.). 
