PULMONARY. 167 



fecundation become more apparent, the cluster formed by 

 these ova(l) becomes less compact, and they are seen to be 

 laterally inserted on several canals. Their great analogy to 

 the ovaries of the Scorpions induces the same observer to pre- 

 sume that they form meshes terminating in two distinct ovi- 

 ducts, which open into a common vulva. The figure of the 

 latter varies ; sometimes it is a longitudinal bilabiated slit, as 

 in the Micrommata argetasia ; sometimes it is protected by an 

 elongated operculum with a caudiform termination, as in the 

 Epeira diadema; and at others resembles a tubercle. 



With respect to the simple eyes, or ocelli, he remarks, 

 that they shine in darkness like those of Cats, and that the 

 Araneides most probably enjoy the faculty both of nocturnal 

 and diurnal vision. 



The abdomen becomes so putrid and decomposed after death, 

 that its colours and even its form are soon destroyed. M. 

 Dufour, by means of a rapid desiccation, the mode of which 

 he points out, has succeeded in remedying this evil to a great 

 degree. 



The silk, according to Reaumur, is first elaborated in two 

 little reservoirs, shaped like tears of glass, placed obliquely, 

 one on each side, at the base of six other reservoirs, resem- 

 bling intestines, situated close to each other, flexed six or 

 seven times, proceeding from a little beneath the origin of 

 the abdomen, and terminating in the papillae by a very slen- 

 der thread. It is in these ^ast mentioned vessels that the silk 

 acquires a greater degree of firmness and other properties 

 peculiar to it; they communicate with the preceding ones by 

 branches, forming a number of geniculate turns, and then va- 

 rious pieces of net-work(2). The newly spun filaments, when 

 first drawn from the mammillae, are adhesive, and a certain 

 degree of desiccation or evaporation is required to fit them for 

 their destined purposes. When the temperature is propitious, 



(1) For their development and that of the foetus, see the admirable work of 

 Herold. 



(2) See Treviranus, on the same subject. 



