464 LECTURE XIX. 



All spiders are oviparous. The mother prepares a soft and warm 

 nest for the eggs, which she guards with great care. If kept from 

 the male the female will lay infertile eggs, and take the same care of 

 them. The Lycosa vagabunda carries her cocoon about with her ; 

 if it be removed, and a ball of cotton substituted, she has been known 

 to bestow upon it the same care ; but when the cocoon was offered 

 ton-ether with the cotton ball, she seldom failed to select her own fa- 

 brication. The Saltica selects an empty snail-shell for her cocoon, 

 and spins a silken operculum aci'oss the mouth. The Epeira fasciata 

 encloses her eggs, which are as big as millet-seeds, in a papyi-aceous 

 cell, surrounded by a cottony covering, which she then suspends by a 

 dozen threads or pillars to a larger chamber of silk. The whole is 

 attached to a branch of a high tree, and is guarded by the mother, 

 who quits it only in extreme danger, and returns when this is past. 



Bonnet, finding in his garden the pit-fall of the larva of the ant- 

 lion, took a spider with her cocoon, and threw them in ; the spider 

 crawled up the side of the pit, but before she could escape the ant-lion 

 seized the cocoon and tore it from the female ; she returned and 

 seized it, and a battle of some minutes ensued. The ant-lion, how- 

 ever, succeeded in mastering the spider and retaining the cocoon. 

 Bonnet then rescued the mother, and placed her at the margin of the 

 pit ; but she refused to abandon her offspring, and remained thei'e, 

 passive, as if she had lost everything that was worth living for. 



The eggs of most spiders are spheroidal. Prior to impregnation 

 the ovum consists of a yolk and delicate yolk-membrane, containing 

 a large germinal vesicle, whose nucleus shows several nucleoli, and, 

 besides this, a peculiar firm corpuscle, discovered by Siebold * and 

 Von Wittich f, usually consisting of fine concentric layers, more 

 seldom granulated, and disappearing in the fully developed ova. 



After one intercourse with the male the Tegenaria civilis has been 

 observed to produce several sets of eggs, intervals of ten months oc- 

 curring between each act of oviposition, and two years elapsing before 

 all the eggs were deposited. 



The impregnated ovum of the spider, at its exclusion, consists of a 

 large and finely granular vitellus, invested by the membrana vitelli, 

 which is separated from the chorion by a very thin structure of 

 colourless liquid, analogous to the albumen or the white of the hen's 

 egg. Tlie yolk is generally of a yellow colour ; but in some species 

 of spider is grey, white, or yellowish brown. The germinal vesicle 

 has disappeared. An opaque, white, elliptical spot indicates, at this 

 period, the metamorphosed and impregnated centre from which sub- 

 sequent development radiates. The previous changes which have 



* XXIV. p. 543. t CCXC. 



