356 AMERICAN SPIDEKS AND THEIR SPINNINGWORK. 



lineweaving adjunct to its web. We have seen it in the case of Argiope, 

 though not so strongly developed and not universall}' possessed by the in- 

 dividuals of that genus. We have seen it more decidedly and 

 Epeira permanently fixed upon Epeira triaranea and Epeira thaddeus. 



. J. But, to a greater or less extent, it may be said tliat the linevveav- 



ridium. ' o > .1 



lug habit belongs to the Orbweavers, though by way of associa- 

 tion with and subordination to their typii'al urhirular snare. 



It may further be worth noting, in this connection, that not all the 

 Epei'roids make use of a round snare. There is a wide difference between 

 the mere sector of an orb made by Hyptiotes and the web made 

 ec era ^^^^ Epeira triaranea or Epeira labyrinthea, and which I have 

 denominated a sectoral orb. Yet the last named snares are only 

 larger sectors of circles, like that of Nephila, for example. By turning to 

 the description of the manner in which the interradials of Nephila are 

 woven in, it will be seen that it substantially resembles that used by Hyp- 

 tiotes and, indeed, by Dictyna, when placing in its spirals of flocculent 

 thread. In other words, the sectoral orlj is made by a series of loops 

 passing over the sector of a circle larger or smaller, as the case maj' l)e. 



Moreover, a very considerable grouj) of the Orbweavers spin horizontal 



orl)s ; and it is interesting to observe that Uloborus, which is related to 



Orbweavers generally by its round web, and to the Tubeweavers 



^rfu^ through Hyptiotes and Dictyna by their nonviscid armature of 



flocculent spirals, spins a horizontal web like that group of the 



EijeiriiiiB to which the Orchard and the Hunchback spiders belong. 



Thus it has been shown that one may pass by natural gradations, 

 through forms more or less distinctly marked, from the simpler and seem- 

 ingly more jirimitive sjiinningwork, to the various orbicular snares, 

 e on- ^^.]jj(-.jj inay be considered the most complex of all known webs. 

 These relationships are often very .striking, and, on the whole, 

 beautifully indicate the industrial unity of the entire order Aranese. 



Nevertheless, no one better knows than the student of spider habits how 

 vast are the intervals which, at many points, have no more substantial 

 bridge than that which imagination or analogy may supply. When arach- 

 nologists shall have more thoroughly wrought out the natural history of 

 spiders, some of these interspaces may be united or more nearly 

 Unity of approached. Perhaps some species have disappeared whose spin- 

 „ . -u. ningwork might have furnished missing industrial links. Never- 

 theless, the veritable facts of science can go no further than to 

 show the points and degree of approach, and exhibit the general har- 

 mony, one might almost venture to say the germinal unity, of industrial 

 haljit which marks the children of Arachne. 



THE END. 



