252 ON THE POISON OF ANIMALS 
observed to accompany the action of swallowing in 
its adversary. 
July 19th. Temperature 70°. A female Agelena 
labyrinthica struck its fangs into the left side of the 
mesonotum of a Flesh-fly, at 12"23™ p.a., and eagerly 
extracted its fluids, the act of deglutition being at- 
tended with the usual nodding motion of the victim. 
After ineffectual efforts to escape, the insect became 
exhausted, and finally expired at 12° 43™ p.m. 
These experiments do not present any facts which 
appear to sanction the opinion that insects are de- 
prived of life with much greater celerity when pierced 
by the fangs of spiders than when lacerated mechani- 
cally to an equal extent by other means, regard being 
had in both cases to the vitality of the part injured, 
as the speed with which existence terminates mainly 
depends upon that circumstance. It is true that the 
catastrophe is greatly accelerated if spiders maintain 
a protracted hold of their victims; but this result is 
obviously attributable to the extraction of their fluids, 
which are transferred by oft-repeated acts of degluti- 
tion into the stomachs of their adversaries. 
From the entire mass of evidence supplied by the 
experiments taken in the aggregate, it may be fairly 
inferred that whatever properties characterize the 
fluid emitted from the orifice in the fangs of the 
Araneidea, it does not possess that degree of virulence 
which is commonly ascribed to it, neither is it so de- 
structive to animal life when transmitted into a recent 
