96 Mr. J. Blackv/all's Observations on the House-Spider, 



p. 184, has elicited an editorial note having reference to an 

 article in theZoologicalJournal, vol. i. p. 283-284, from which. 

 on a hasty perusal, it might be supposed that this instinct is 

 sometimes manifested by the house-spider when so situated. 

 But as it must be conceded, on mature deliberation, that au 

 inference precipitately deduced from a single, and, on the 

 writer's own showing, unsatisfactory experiment, cannot be 

 considered as at all invahdating the conclusion at which I have 

 arrived after a careful and extensive investigation of the sub- 

 ject, I should scarcely have deemed it requisite to bestow a 

 comment on what he has written, had I not felt called upon 

 to do so by the allusion made to it in the above-named scien- 

 tific publication. Unforeseen obstacles, which it would be 

 tedious to particularize, have concurred to prevent me carry- 

 ing my intention into effect so early as I could have wished. 



In order that the statement of this observer, whose views in 

 more instances than one are opposed to my own, may be duly 

 appreciated, [ shall transcribe it at length, offering at the 

 same time such animadversions upon it as a candid examina- 

 tion of its claims to the attention of naturalists has suggested. 



" Some years ago," he remarks, " when making some ob- 

 servations on the habits of spiders, I was struck with the fol- 

 lowing circumstance, which I have never found in any author 

 on the subject. I insulated a common house-spider, by pla- 

 cing it on a little platform, supported by a stick with a 

 weight at the bottom, in the middle of a rummer of water. 

 The platform was about half an inch above the surface, which 

 was nearly even with the top of the glass. It presently made 

 its escape, as was anticipated, by suffering a thread to be 

 wafted to the edge of the glass; but supposing that it might 

 have been assisted by the water being so nearly on the same 

 level, I poured some of it away, and placed the spider as be- 

 fore. It descended by the stick till it reached the water, and 

 examined with its two anterior feet all round, but finding no 

 way to escape, it returned to the platform, and for some time 

 prepared itself by forming a web, with which it loosely en- 

 veloped the abdomen, by means of the hinder legs. It then 

 descended, without the least hesitation, into the water, to the 

 bottom ; when I observed the whole of the abdomen covered 

 with a web containing a bubble of air, which I presume was 

 intended for respiration, as it evidently included the spiracles. 

 The spider, enveloped in this little diving-bell, endeavoured 

 ''ton every side to make its escape, but in vain, on account of the 

 " slipperiness of the glass; and after remaining at the bottom of 

 the water for thirteen minutes, it returned apparently much 

 exhausted, for it immediately coiled itself closely under the 

 little platform, and remained afterwards without motion. This 



