AUACIIXIDA. 



461 



at the breeding season with sperm- cells and their characteristic nuclei 

 or "spermiitoa," from which the spermatozoa are afterwards developed. 

 TJie second or copulatory part of the generative organs is confined 

 to the two last joints of the maxillary palp (ib- c, d) ; the dilatation 

 of these joints is chiefly formed by a spoon-shaped membranous tube 

 or sac, commencing at the penultimate and reaching its greatest ex- 

 pansion at the last joint {d) : tliis tube appears to line a cavity in the 

 ordinary state ; but it can be distended, everted, and erected, when it 

 is seen to be terminated by a horny appendage. In this sac the 

 spermatozoa are found both free, and in the interior of the sperm- 



173 



Tpgenaria domestira. 



Kpcira dud^nia. Female organs. 



cells, having escaped from the spermatoa into the cavity of the parent 

 sperm-cell. 



In the female spider the ovarium sometimes presents the form of a 

 simple elongated fusiform vesicle (/fg. 170, o), closed at one ex- 

 tremity and communicating with a slender oviduct (p) at the other, 

 which duct, after more or fewer convolutions, terminates at the cor- 

 responding angle of the simple transverse vulva. It is situated, like 

 the outlets of the vasa deferentia, between the pulmonary stig- 

 mata {b, h). Each ovarium {fig. 173, c) is divided in the Epeira, or 

 diadem-spider, l>y a median septum, and the eggs are laid at two 

 distinct periods. The ducts {b) are short, and terminate each by a 

 distinct orifice (a) within the transverse vulva. In the common 

 house spider the ovisacs are developed, like grapes, from a central 

 stem-like ligament, to which they are appended by slender peduncles, 

 the whole being inclosed in tlie common capsule. The short vagina 

 or vulva receives the ducts of two sperm -reservoirs; they are of 

 a brown colour and horny texture, and are attached to the skin. 



