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Aratu (grapsus pictusj. It is pounded, and a potion made 
of it with wine : it acts as an emetic. 
The ancients, in like manner, boast of the anti-poisonous 
qualities of the Crustacea, and the employment of them may 
certainly prove salutary, in circumstances where the use of 
alkalies is required. M. Arthaud has caused death to 
chickens, by causing them to be stung by the large crab- 
spider of the Cape of Good Hope (mygale cancerides, Lat.). 
This species, according to him, frequents humid places, kills 
and sucks large insects, kakerlaks, and often its own con- 
geners. He maintains that this mygale often perishes, by 
the sting of a sort of gadfly under the belly, most probably in 
the organs of respiration. The touching of this last arane'ide, 
or rather its hairs, produce severe smartiugs, similar to those 
caused by the introduction of the hairs of certain caterpillars, 
into the epidermis. 
Though sound criticism may authorize us to call in doubt, 
or suspect of exaggeration or partiality, the testimony of some 
travellers, or of some historians respecting the venomous 
powers of these arauei'des, prudence, enlightened by observa- 
tion, forbids us to deny the existence of their poison, or to 
lull ourselves in a fancied security against the dangers which 
it may occasion. Here, as in so many other cases of uncer- 
tainty, further experiments will be necessary to decide our 
judgment. 
The hairs of these mygales, as we have already hinted, 
make the same impression upon the skin as the hairs of cer- 
tain caterpillars. “ One morning, as I was getting up, one 
ol the Spanish travellers made an exclamation on seeing on 
my garments, from the feet even to the shoulders, a brown trace, 
occasioned by the passage of one of these crab-spiders, and by 
an acrid and caustic liquor which distils continually from 
its mouth and feet. Happily it passed innoxiously while I 
was sleeping profoundly, and contented itself with thus 
