414 REVIEWS. 



individuals thus insulated be exposed to a current of air, either naturally or artifi- 

 cially produced, they immediately turn the abdomen in the direction of the breeze, 

 and emit from the spinners a little of their viscid secretion, which being carried out 

 in a line by the current, becomes connected with some object in the vicinity, and 

 affords them the means of regaining their liberty. If due precaution be used in 

 conducting this experiment, it plainly demonstrates that spiders are utterly inca- 

 pable of darting lines from their spinners, as they cannot possibly escape from their 

 confinement on the twigs in situations where the air is undisturbed, but in the agi- 

 tated atmosphere of an inhabited room, they accomplish their object without 

 difficulty. Similar means are frequently employed by spiders in their natural 

 haunts, for the purposes of changing their situation and fixing the foundation of 

 their snares." 



The habits of spiders however are little known. The subaqueous 

 habitation of the water spider (Argijroneta) indeed is well known 

 from the descriptions of Dr. Bell and others, and according to Mr. 

 Blackwall — 



" The following remarkable physiological facts in connection with Tegenaria 

 civilis (one of the house spiders) have been ascertained by observation and expe* 

 riment ; namely, that both sexes change their integument nine times before they 

 arrive at maturity, once in the cocoon, and eight times after quitting it; that a leg 

 of a young individual, detached at the coxa (hip) six times consecutively, maybe re^ 

 produced at each succeeding change of integument after the infliction of the injury; 

 that the life of the species extends through a period of four years; that the sexual 

 organs of the male are connected with the digital joint of the palpi; and that the 

 female, after impregnation, is capable of producing nine sets of prolific eggs in suc- 

 cession, without renewing her intercourse with the male, more than two years elaps- 

 ing before all are deposited, and ten months nearly intervening sometimes between 

 the deposition of two consecutive sets." 



It is well known that spiders are essentially insectivorous and 

 like other animals of prey they can go a long while without food, 

 A female Theridion cpcadripunctatum has been known to exist for 

 eighteen months without nutriment in a phial closely corked. 



Though unsocial and voracious, many spiders have, in their affec- 

 tion for their young, at least one redeeming feature. They lay from 

 thirty to two hundred eggs at once, and " usually spin silken cocoons 

 " for their reception, which exhibit much diversity of form, colour, 

 " and consistency, and are placed in various situations, according to 

 " the economy of the species, by which they are fabricated. Many 

 " spiders abandon their cocoons so soon as they are completed ; 

 " others manifest great attachment to them, watching over them with 

 " the utmost solicitude ; and some, connecting them with the spin- 

 " ners by silken lines, or grasping them with the falces and palpi, 

 " transport them whenever they move." In some species the young 

 spiders on leaving the cocoon attach themselves to the body of their 

 parent, who carries them about until they are able to provide for 

 themselves. 



With reference to the senses of the Arachnida, Mr. Blackwall 

 says : — 



" Nothing is known with certainty concerning the organs of smell and hearing 

 in spiders. As regards taste, the choice which these animals make of their food 

 sufficiently indicates that it exists, and it is probable that the organ id situated at the 



