ANIMALS OF THE ORDER ARANEIDEA. 35 



September 10th. Temperature 65°. At l h 13 m p.m. a common Crane-fly was pierced 

 through the left side of the abdomen, near the middle, with a fine needle ; the insect ex- 

 pired on the same day, at 5 h 29 m p.m. 



September 10th. Temperature 65°. The point of a strong needle was deeply inserted 

 into the right side of the abdomen of a large Green Grasshopper, near its anterior extre- 

 mity, at l h 20 m p.m. Though the injury was severe, the life of the insect did not become 

 extinct till 7 h 41 m p.m. on the 12th. 



September 10th. Temperature 66°. The right side of the abdomen of a common "Wasp 

 was penetrated near the middle with the point of a fine needle, at 2 h 5 m p.m.; a transpa- 

 rent fluid oozed from the puncture, and the life of the wasp terminated at 10 h 20 m p.m. 



September 18th. Temperature 60°. A male Tegenaria civilis deeply inserted its fangs 

 near the middle of the mesonotum of a House-fly, Musca domestica, at 10 h 10 m a.m., and 

 retained its hold for more than an hour and a half. The victim continued to manifest 

 unequivocal signs of life till 10 h 44 m a.m., and appeared to sink gradually from mere ex- 

 haustion. All the time it was in the grasp of its enemy, with the exception of short 

 intervals, it was perceived to have a slight nodding motion, which was discovered to be 

 caused by the act of deglutition on the part of the spider, a synchronous motion being 

 always observed in the fluid suddenly and copiously propelled into the spider's mouth, 

 and then by degrees reduced in volume in exact proportion to the continuance of the 

 nutation. Whenever the fluid was withdrawn from the mouth a fresh supply was speedily 

 introduced, and after mingling with that extracted from the body of the fly, was conveyed 

 into the stomach of the spider by a repetition of the act of swallowing, thus occasioning 

 the nodding motion with intervals of repose apparent in its prey. 



September 18th. Temperature 61°. At 10 h 20 m a.m. a female Tegenaria civilis seized a 

 House-fly with its fangs near the middle of the mesonotum, and did not relax its hold for 

 more than an hour. The struggles of the fly became gradually more feeble, till they 

 ceased altogether at 10 h 47 m a.m. The nodding motion of the victim, and all the attendant 

 circumstances, were as conspicuous in this instance as in the preceding one. 



September 18th. Temperature 64°. A female Segestria senoculata penetrated with its 

 fangs the right side of the mesonotum of a House-fly at l h p.m., but did not deprive it of 

 life till l h 29 m p.m. The spider kept its hold about an hour ; and a nodding motion of the 

 fly, regularly accompanied by the act of deglutition in its destroyer, with brief and simul- 

 taneous pauses in both, was observed during the entire period. 



1847. July 15th. Temperature 71°. At 5 h 3 m p.m. a brilliant Green Fly, Musca cmsar, 

 was pierced by the fangs of a female Agelena labyrmthica near the posterior extremity of 

 the abdomen, on the under side. After retaining its hold about ten minutes the spider 

 transferred it to the middle of the mesosternum, perforating the part and rapidly extract- 

 ing the fluids of its prey, whose existence terminated at 5 h 26 m p.m. A nutation of the fly 

 was constantly 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 Mesh-fly, at 12 h 23 m p.m., and eagerly extracted its fluids, 

 the act of deglutition being attended with the usual nodding motion of the victim. After 

 ineffectual efforts to escape the insect became exhausted, and finally expired at 12 h 43 m p.m. 



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