ANIMALS OF THE ORDER ARANEIDEA. 35 
September 10th. Temperature 65°. At 1" 13” 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^ 29" 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 1'20" p.m. "Though the injury was severe, the life of the insect did not become 
extinct till 7° 41" 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^ 5" p.M.; a transpa- 
rent fluid oozed from the puncture, and the life of the wasp terminated at 10^ 20" 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" 10" 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" 44” A.w., 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 Whenever the fluid was withdrawn from the mouth a fresh supply was speedily 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° 20" 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^ 47" a.m. The nodding motion of the victim, and all the attendant 
cireumstances, 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 1° P.M., but did not deprive it of 
life till 1° 29" 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" 3" p.m. a brilliant Green Fly, Musca cæsar, 
was pierced by the fangs of a female Agelena labyrinthica 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" 26" PM. 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 Flesh-fly, at 12^ 23” r.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^ 43^ p.m. 
F2 
