spiders: their structure and habits. b\) 



down the stems of plants. It is among the largest of British 

 spiders, the female being nearly an inch long in the body ; and it 

 mostly inhabits fenny districts. 



Beside these two species, it has been found by experiment 

 that a few others, belonging to a distinct family — Nericne longi- 

 palpis^ for example — will exist in a state of activity for several 

 days submerged in water, spinning their lines and behaving all 

 the time just as in air. 



The feet of the Hunting-spiders are somewhat differently 

 furnished from those of their Retiary brethren. Each foot has 

 two claws and a scopula, or brush, designed like the tarsal 

 cushions on the feet of flies and other insects, to enable them to 

 run up polished surfaces, or to walk along them in an inverted 

 position. The brush consists of a number of shafts springing 

 from the base of the tarsus under the claws, shghtly curved, 

 slender at the base and expanded at the extremity. Each shaft 

 is fringed with fine hairs, and its extremity on the under-side is 

 covered with a multitude of hair-like papillae, which not only give 

 the animals a mechanical hold on smooth surfaces by the friction 

 arising from so many points of contact, — amounting in a specimen 

 of the My gale avicularia to 400,000 on each foot, — but they also 

 emit a viscid secretion which adheres to the surface with a 

 tenacity sufficient to sustain their weight. 



Some of the genus Salticiis have been observed to use these 

 brushes to wipe and polish the cornea of their two front eyes, 

 which are unusually large and prominent. 



The Burrowing Spiders afford good examples of ingenuity 

 and perfection of workmanship in the construction of their 

 habitations and snares. To this class belong some of the Agelence 

 (foragers); and one species, the A. labyri?ithica, is common enough 

 on open banks where the herbage is coarse and the surface 

 irregular. It spins a horizontal web of a compact texture, and 

 fabricates a tube of white silk conducting to, or serving for, its 

 retreat ; at the mouth of this it watches, and yet is not easily 

 captured ; for it pops into the tube and disappears on the slightest 

 alarm. It is readily distinguished by the length of its spinnerets, 

 the upper pair being three-jointed, and projecting far beyond the 

 others ; while the spinning-tubes are placed in a row along the 

 under surface of the terminal joint. When we come to examine 

 closely the silken tube woven by this spider, we discover a cause 

 for their unusual length. It is a compact tissue impervious to the 

 smallest grains of sand, and made by a process analogous to that of 

 weaving. Instead of the tips of the spinning-tubes being brought 

 to meet in a point, as when a strong thread is to be spun, the 

 tubes of the lower pair of spinnerets are erected so as to be brought 

 parallel to each other, and thus a band of fine parallel filaments is 



