318 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



inch. The materials of which it is composed externally are small particles 

 of hardened earthy pebbles, twigs, withered leaves, etc., rather slightly at- 

 tached by threads. This tube is lined with silk, forming a comfortable 



home. However irregular in appearance the nest may 

 be externally, the interior is always smooth. 



Mr. Robertson examined sixty or seventy nests, and 

 kept a dozen of them under glass cases for closer ob- 

 servation. Most of the nests were suspended under the 

 leaves of raspberry and gooseberry bushes and like situ- 

 ations at a distance of from two to four inclies from 

 the earth ; in a few instances they were suspended in 

 the angles of old walls. When built above the soil the 

 pebbles alone seemed to be used. When built near a 

 wall particles of mortar were taken. In the latter case, 

 the nests were the most regular in form. When with- 

 ered leaves were near, these and small twigs were used, 

 and the nests formed of such materials were the least 

 It is thus manifest that the mechan- 



FiG. 295. Nest of Therid- 



ium riparium, made of symmetrical. 



ical finish of the domicile depends largely upon the 

 building material available. 



In order to test the capabilities of these little architects, the observer 

 supplied those which were in confinement w^ith small twigs cut in lengths 

 of about one-eighth inch, mixing with them larger pieces. He 

 Artiiicial ^^,.^g surprised to find that the smallest pieces were not often 

 Used selected, and apparently the most unsuitable pieces were fre- 



quently chosen by the little architect. Figs. 298 and 299 are 

 examples of nests formed by these twigs. The upper parts, above the 

 marked line in the cuts, were built before they were transferred to cases. 

 Fig. 298 was constructed in the course of three weeks. Fig. 299 was built 

 by a wonderfully industrious mother of two large families, who subse- 

 quently made a neat little residence of particles of chalk. 



While the eggs remain unhatched, the nest seldom exceeds one inch in 

 length. No sooner, however, does the mother find that she has to accom- 

 modate a large family than she is seized 

 with a building impulse, and may be seen 



to descend suddenly to the earth. 



Mode of oi ii , 1 -1 



T3 ■■,-,. ohe then takes a seemmgly pur- 

 poseless scramble over the material 

 beneath her nest. Passing by much build- 

 ing material apparently well fitted for her 

 purpose, without any attempt at examination, 

 she fixes upon a twig or other object which 

 often appears disproportionate to her size and strength. To this she attaches 

 a line, and (quickly scrambles back again, dragging the twig after her. 



Fig. 296. 



Fig. 297. 



Nests in their earliest stages. 

 (Theridiimi riparium.) 



