STRENGTH OF WEBS AND POWER OF SPIDERS. 245 



Governor Knott also sent me the foregoing (Fig. 223} memory sketch 

 of the position of the mouse and the characteristics of the snare and the 

 entangling lines. ^ 



The testimony and observations thus obtained are of such a char- 

 acter as to establish beyond any doubt these facts : First, that a young 

 living mouse was in some manner securely entangled in the 



, . snare of a spider. Second, that the spider, by means of silken 



elusion. . '^ . 



lines two or three feet long, hoisted the mouse through a 

 perpendicular distance of four or four and a half inches. Third, that 

 the mouse was entangled in the spider's web by the tail alone, and 

 although it lived for at least ten hours, during which it struggled 

 vigorously to escape, was unable to free itself, and finally died. Fourth, 

 that the hoisting process continued during Monday from about 11 A. M. 

 until the night of Tuesday following, a period of thirty-four hours, 

 when the web was accidentally broken, and then brushed away. Fifth, 

 that the specific identification of the spider heroine of this exploit was 

 at first somewhat in doubt ; and the credit seemed to lie between a Tube- 

 weaver, the Medicinal spider (Tegenaria medicinalis), and the common 

 Lineweaver (Theridium tepidariorum). The accounts of the captor's be- 

 havior during the hoisting of her victim, especially swathing her victim, 

 and the opinions of the various eye witnesses to whom were sent descrip- 

 tions and drawings of both species and their characteristic webs, point to 

 the Lineweaver, I was much perplexed by the conflicting testimony in- 

 evitable in the reports of the several untrained observers. But persistent 

 corresi:)ondence and the kindness of Mr. Hopper and others finally pro- 

 cured me specimens which were declared to be undoubtedly identical 

 with the mouse catcher. These specimens are Theridium tei)idariorum ; 

 to this spider, therefore, must be given the credit of the achievement.^ 

 Sixth, a comparison of the weight of a young mouse ^ with the actual 

 power of resistance in webs of both Theridium tepidariorum and the 

 Medicinal spider, as determined by a number of tests, shows that the 

 incident on such grounds is not only plausible but much within the 



^ " The figure intended to represent the spider is lai^r in proportion to that insect than 

 the mouse is to the unlucky little rodent it is supposed to suggest. The length of the line 

 attached to the taU is much shorter in the sketch than in the original, where it must have 

 been three feet or over, as the web from wliich it wa.« piisiK>ndod was woven ujKin the bot- 

 tom of a writing desk, and, as nearly as I can remeiul)er, in the t^haix' presented, but much 

 larger." — Mr. Knott's letter. 



2 Specimens sent to me of the spiders supposed to be identical with the one that caught 

 the mouse, taken from the siime desk and from a web of similar ronstniction, were the 

 ^Medicinal spider. Also, a specimen of a web somewhat similar to the one in whith the 

 mouse was entangled, and a descrii>tion with estimated measurements, of the extensive pro- 

 portions of the original snare, point in the s;une direction. 



' "A mature male mouse weighed three hundRvl and fifty-six grains. One half grown 

 would probably weigh about one-sixth to one-fourth of this, s;iy from sixty to ninety grains." — 

 Note from Dr. Joseph Leidy. 



