COMPARATIVE , COCOONING INDUSTRIES. 177 



VI. 



6. A sixth basis of comparison is the multiplex cocoonery of certain 

 species. The general habit among spiders is to make but a single cocoon 

 at a time, and most females probably limit their maternal duty 

 of Co ^^ *^^® production of one egg sac. But there are numerous ex- 

 coons, ceptions, which have been noted. Among Orbweavers the Laby-' 

 rinth spider, the Tailed spider, the Basilica spider, and some 

 others habitually produce several cocoons. These are not made contempo- 

 raneously, but are spun consecutively, with intervals of several days be- 

 tween each cocoon, so that the younglings will be hatched from the first 

 brood while the last is yet freshly laid. 



It is to be noted, also, that even those spiders that ordinarily limit 

 themselves to one cocoon, as Argiopo, under certain conditions, which are 

 not fully understood, produce two or more cocoons. Epeira, when specially 

 nourished, is said to produce several. The fecundity of the spider may 

 therefore be said to be subject to variation, and the disposition to multi- 

 ply cocoons is dependent, more or less, upon the fecundity. 



Among the Retitelariic numerous species are found spinning several 

 cocoons, the most familiar example being Theridium tepidariorum and 

 Latrodectus. The Tubeweavers also have some remarkable representatives 

 of multiplex cocoonery, as, for example, certain species of Dictyna and 

 Segestria. The cocooning habits of the Territelariae are so little known 

 that one cannot speak positively, but it is probable that no Tunnelweaver 

 makes more than one cocoon. 



Among the Wandering spiders the single cocoonery which characterizes 

 the Tunnclweavers is the rule. I know no Saltigrade and no Laterigrade 

 that produces more than one cocoon, although of the former Staveley says 

 that Epiblemum scenicum makes one or two, and of the latter that Philo- 

 dromus cajspiticolis deposits two flattened cocoons in a large nest.' Among 

 Citigrades I know no species except Pucetia aurora; this spider produces 

 at least two cocoons, that are concealed within a little nest of crossed lines, 

 very much after the fashion of that constructed by Dolomedes. No doubt, 

 however, a wider knowledge will compel us to include other species in 

 this group. 



This summary of facts points to those conclusions: First, that the three 

 Tribes which are by especial eminence Sedentary possess the greatest 

 number of species that make more than one cocoon. Seconil, that the 

 three Tribes that arc conspicuously Wanderers make but one cocoon, with 

 rare exceptions. Third, that the Tunnclweavers, whose habits sometimes 

 approach one group and sometimes another, but in the matter of cocoonery 

 resemble the Citigrades, as regards multiplex cocoonery are to be classed 

 with the Wanderers, apparently limiting themselves to a single egg sac. 



' "Brit. Spidera," pages 57 and 85. 



