34 MR. J. BLACKWALL ON THE POISON OF 
3. Experiments on Insects. 
1846. August 7th. A female Zpéira diadema inflicted a severe wound on the mesono- 
tum of a common Wasp, near the base of the right anterior wing, at 11" a.m., the tem- 
perature at the time being 74°. The wasp, though disabled from flying, survived the 
injury for the space of thirteen hours. 
August 7th. At 1° 30" p.m., the temperature being 72°, a female Epéira diadema 
pierced a Humble-bee, Bombus terrestris, with its fangs near the posterior part of the 
mesosternum. ‘The wound deprived the humble-bee of the power of flight, but did not 
terminate fatally till 11° p.m. on the 10th. _ 
August 8th. Temperature 68°. A female Segestria senoculata seized a Flesh-fly, Musca 
vomitoria, near the middle of the tibia of the right posterior leg, and did not quit its hold 
for several seconds. A transparent colourless fluid issued from the wounds made by the 
fangs of the spider, but the fly retained the use of its wings, and did not expire till even- 
ing on the 10th. | 
August 13th. Temperature 64°. At 5^ 15" p.m. a female Segestria senoculata inserted 
its fangs about the middle of the abdomen of a large Green Grasshopper, Acrida viridis- 
sima, and retained its hold, which it quitted voluntarily, for many seconds. A greenish- 
yellow fluid flowed copiously from the punctures, yet the insect continued to be lively in 
its movements, leaping with agility up and down the glass vessel in which it was confined, 
and ceased not to exist till midnight on the 15th. 
August 14th. Temperature 66°. A female Epeira diadema pierced a large Green Grass- 
hopper at 4^ 43" P.M., burying one fang at the base of the antenna on the right side, and 
the other in the right eye. The spider retained its hold for several seconds, and on quit- 
ting it a greenish-yellow fluid issued from the former wound and a dark brown fluid from 
thelatter. Notwithstanding the serious injuries the grasshopper had received, no dimi- 
nution of its activity was apparent, and it did not expire till afternoon on the 16th. 
August 29th. Temperature 69°. At]1^ 22" P.M. a Hive-bee had its abdomen extensively 
lacerated near the middle of the left side by a female Epéira quadrata. A large quantity 
of transparent fluid flowed from the wound, but death did not ensue till 3^ 18" p.m. 
September 3rd. Temperature 68°. A common Crane-fly, Tipula oleracea, punctured 
by the fangs of a female Segestria senoculata, at 4^ 35” P.m., about a quarter of an inch 
from the posterior extremity of its abdomen, survived till 8^ T" P.M. | 
September Tth. Temperature 69°. At Ir 45» P.M. a Flesh-fly was bitten by a female 
Epéira diadema on the under side of the abdomen, near its posterior extremity, and a 
brownish fluid continued to ooze from the wounds till 5°18" p.a. on the 8th, when the fly 
September 7th. Temperature 68°. 
A common Crane-fl i i 
xtrémity of the lbs M cpu y was seized near the posterior 
; P.M., by a female Epeira quadrata. A brownish fluid 
issued from the punctures made by th i : : 
à y the fangs of the spider, and the exi 
[ed at 6 9» p yr. en p an e existence of the insect 
S ee 
eptember 10th. Temperature 64°. Pierced a Flesh-fly through the middle of the left 
side ds the abdomen with a fine needle, at 1% 14" P.M.; a transparent fluid issued from the 
wound, which the fly survived till 4^ 20" P.M. on the 11th. 
