SPIDERS AND MITES 



jointed, for all the spinnerets spring from wart-like sock- 

 ets, which may be considered as basal joints; and as the 

 circlet of bristles in the first pair doubtless indicates a 

 short joint, sunken as it were within the preceding, this 

 pair is likewise three-jointed; the middle pair appears to 

 be but two-jointed. 



The minute horny tubes are themselves composed of 

 two joints, the basal one thick, the terminal one very 

 slender, and perforated with an orifice of excessive tenu- 

 ity; through which the gum oozes, at the will of the 

 animal, as an equally attenuated thread. On our Clubiona^ 

 the number of tubes in all the spinnerets is about three 

 hundred; but in the Garden Spider (Epeira) they exceed 

 a thousand. 



This remarkable multiplicity of the strands with which 

 the apparently simple and certainly slender thread of the 

 Spider is composed, has attracted the attention of those 

 philosophers who seek to discover the reasons of the phe- 

 nomena they see in nature. The explanation was first 

 suggested, I believe, by Mr. Rennie, 1 but it has been 

 amplified with much force by Professor Jones, in the 

 following words: 



"A very obvious reflection will here naturally suggest 

 itself, in connection with this beautiful machinery; why, 

 in the case of the Spider, it has been found necessary to 

 provide a rope of such complex structure, when in so 

 many Insects a simple, undivided thread, drawn from the 

 orifice of a single tube, like the thread of the Silkworm, 

 for instance, was sufficient for all required purposes. 

 And here, as in every other case, it will be found, on 



1 "Insect Architecture," 337. 



