202 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



Evidently in tliis case, as vvitli the Argiopes, the mother acted under 

 the impulse of a mcntalism that was without reasoning; or, if we may 

 suppose that she reflected upon the loss of her eggs, such reflection had 

 not sufficient influence upon her will to resist the instinctive impulse — 

 or shall we say the simple functional impulse? — to brood upon something. 

 These cases remind one of the well known persistence of setting hens in 

 brooding over an empty nest. 



The English observer, Mr. F. M. Campbell, records a like example. 

 While watching a female Tegenaria guj'onii lay her eggs, it occurred to 

 . him to see what she would do if these were removed. Accord- 

 ingly the eggs were deftly lifted away, but somewhat to the 

 disturbance of the mother. After a few seconds she began to ovei-spin the 

 spot where she had just placed her eggs, and completed her cocoon.^ Mr. 

 Campbell's suggestion, that the force of habit urged forward the aranead 

 to act as though the eggs were in the proper site, must be qualified by 

 the fact that "habit" cannot have much influence in a maternal act which 

 is repeated so few times as with this species. There is more plausibility 

 in the physiological aspect of the act which he suggests, viz., that the 

 maturity of the eggs may have been correlated with greater activity in the 

 collection of fluid by the spinning glands ; and, as in the case of the mam- 

 mae of a vertebrate, the discharge of their contents may have been neces- 

 sary for the comfort of the creature. 



X. 



It is impossible not to note the many evidences of exact mechanical 

 skill and design shown by spiders in the act of cocooning. We speak of 



this, no doubt properly, as instinctive. Certainly it is not the 

 g, .J, result of experience, for even in the case of those spiders that 



make several cocoons, the first one is finished with the same 

 accuracy, and indeed after the same methods, as the last. It cannot result 

 from instruction, for in the great majority of cases the young are never 

 associated with their mother ; and in those cases, as among Saltigrades and 

 Lycosids, where the spiderlings are under maternal watch for a little season 

 after hatching, the idea of instruction in the art of cocoon making is not 

 to be thought of. Neither can we suppose this remarkable mechanical ac- 

 curacy to be the result of observation, though no doubt it might happen 

 that immature females observe the methods of cocooning practiced by 

 mature specimens of the various families. In short, the only admissible 

 conception is that the act, including all the methodical details, is intuitive, 

 and springs into being in full operation at the moment that it is needed, 

 and that without any previous preparation or knowledge of any sort on 

 the part of the aranead mother. 



' On Instinct, Trans. Hertfordshire Natural Hist. Society, Vol. HI., page 3, Dec, 1884. 



