370 ARACHNIDA—ARANEAE CHAP. 
formosa, which preys upon the gigantic spider Lurypelma hentzit, 
wrongly styled in America the “tarantula,” but really belonging 
to an entirely different family, the Aviculariidae. 
Fabre’s most interesting researches have established the fact 
that the instinct of the wasp leads it to sting the spider in a 
particular spot, so as to pierce the nerve ganglion in the thorax. 
The precision with which this is effected is absolutely necessary 
for the purpose of the insect. If stung elsewhere, the spider is 
either incompletely paralysed, or it is killed outright, and thus 
rendered useless as food for the future larvae of the wasp. On 
the one hand, therefore, the Tarantula has acquired the habit of 
striking the wasp in the only point where its blow is instan- 
taneously fatal, while on the other the wasp, with a different 
object in view, has been led to select the precise spot where its 
sting will disable without immediately destroying the spider. 
The latter case is, 1f anything, the more extraordinary, as the 
insect can hardly have any recollection of its larval tastes, and 
yet it stores up for progeny, which it will never see, food which 
is entirely abhorrent to itself in its imago state. 
Spiders taken from the egg-nests of wasps by M‘Cook survived, 
on the average, about a fortnight, during which period they 
remained entirely motionless, and would retain any attitude in 
which they were placed. 
There are many animals which either habitually or occasionally 
feed upon spiders. They are the staple food of some humming- 
birds, and many other birds appear to find in them a pleasing varia- 
tion on their customary insect diet. These creatures, moreover, 
are destructive to spiders in another way, by stealing the material 
of their webs, and especially the more closely textured silk of their 
ege-cocoons, to aid in the construction of their nests. M‘Cook 
has observed this habit in the case of Vireo noveborocensis, and he 
states, on the authority of others, that the “Plover” and the “Wren” 
are addicted to it. The smaller species of monkeys are extremely 
fond of spiders, and devour large numbers of them. They are 
said, moreover, to take a mischievous delight in pulling them in 
pieces. Armadillos, ant-eaters, snakes, lizards, and indeed all 
animals of insectivorous habit, draw no distinction between 
Insecta and Arachnida, but feed upon both indiscriminately. The 
army ants, so destructive to insect life in tropical countries, 
include spiders among their victims. These formidable insects 
