TARSAL- COMB IX SPIDERS. 181 



UlohoridcE^ manufacture their fiakey* silk with the curved series of 

 bristles on the metatarsi. But no ; there appeared to be no 

 calamistrum, and we sought elsewhere for explanation. After very 

 little examination with an ordinary platyscopic lens, we ascertained 

 the presence beneath the tarsi of the fourth pair of legs of a comb- 

 like series of curved spines, unlike anything noticeable in other 

 spiders, so far as we have observed them. 



A detached leg speedily placed beneath an inch objective 

 confirmed our observation, and our hasty conjecture as to the 

 import of this comb, which we then saw to be exactly adapted to 

 the carding out of multitudes of fine threads, each thread kept 

 separate^ although we had not yet actually witnessed the opera- 

 tion. This comb consists of nine stout spines, situate in single 

 rows beneath the tarsus of the hind pair of legs only, firmly articu- 

 lated to the joint, strongly curved and directed towards the apex 

 of the joint, their slender points aculeate and slightly, not abruptly, 

 recurved; their outer sides being emarginate with a series of 

 tooth-like barbs, becoming more highly developed towards the 

 foot-claws. These are supplemented on either side by other stout 

 bristles. (N.B. — That which is a hair under a pocket lens becomes 

 a bristle under a higher power, and the bristle becomes a spine, 

 when described.) Further up the joint the spines begin to show 

 a tendency to curvature and toothedness, developing only to a 

 definite extent, however, towards the apex of the joint, showing 

 probably that the origin of this comb was due to a chance 

 unevenness in the surface of the curved bristles, which has been 

 accentuated, owing to the advantage their presence has conferred 

 upon their owners, becoming from" generation to generation stouter 

 and more adapted for real utility, finally resulting in the highly 

 useful instrument we now observe. 



Of course, this is a mere conjecture drawn upon the line of 

 thought which is predominant in our minds, now brimful of ideas 

 of natural selection, adaptation to environment, and the survival of 

 what is most fitting and useful to the individual. To speak of a 

 chajice variation is to shirk the vital point, viz., the real origin of 



* Flakey and Flocculent are misnomers when applied to this silk. They 

 must here be regarded as applying to the appearance, and not to the real 

 nature of the silk. 



