34 MR. J. BLACKWALL ON THE POISON OF 



3. Experiments on Insects. 



1846. August 7th. A female Epeira diadema inflicted a severe wound on the mesono- 

 tum of a common Wasp, near the base of the right anterior wing, at ll h 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 l h 30 m p.m., the temperature being 72°, a female Epeira 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 ll h 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 h 15 m 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 h 43 m 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 

 the latter. 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 l b 22 m p.m. a Hive-bee had its abdomen extensively 

 lacerated near the middle of the left side by a female Epeira quadrata. A large quantity 

 of transparent fluid flowed from the wound, but death did not ensue till 3 h 18 m p.m. 



September 3rd. Temperature 68°. A common Crane-fly, Tipula oleracea, punctured 

 by the fangs of a female Segestria senoculata, at 4 h 35 m p.m., about a quarter of an inch 

 from the posterior extremity of its abdomen, survived till 8 h 7 m p.m. 



September 7th. Temperature 69°. At l b 45 m p.m. a Flesh-fly was bitten by a female 

 Epeira diadema on the under side of the abdomen, near its posterior extremity, and a 

 brownish fluid continued to ooze from the wounds till 5 h 18 m p.m. on the 8th, when the fly 

 expired. 



September 7th. Temperature 68°. A common Crane-fly was seized near the posterior 

 extremity of the abdomen, at 4 h 54 m p.m., by a female Epeira quadrata. A brownish fluid 

 issued from the punctures made by the fangs of the spider, and the existence of the insect 

 terminated at 6 h 9 m p.m. on the 8th. 



September 10th. Temperature 64°. Pierced a Flesh-fly through the middle of the left 

 side of the abdomen with a fine needle, at 12 h 14 m p.m.; a transparent fluid issued from the 

 wound, which the fly survived till 4 h 20 m p.m. on the 11th. 



