NESTING HABITS AND PROTECTIVE ARCHITECTURE. 



29- 



might think at the first glance that they had been thus distributed with 

 aesthetic intent. They are, however, simply the result of accident, caused 

 by the restless movements of the spider around and around her room, and 

 by the habit just alluded to. Out of the front door stretches the trapline, 

 to which the fore claws of the spider are clasped; and towards the back 

 part of the room, fastened to the spinnerets and probably clasped occa- 

 sionally by the hind feet, there is another line which anchors the spider 

 to her nest. Thus, both fore and aft, this truly domestic creature has 

 strong attachments to her home. 



In order to test the ability of Insularis to adapt her nesting haVjits to 

 change of plant environment, I selected several that had made nests in 

 several leaves of oak and in clustered leaves of sumac. These 

 I transferred to some coniferous trees (spruce) standing upon a 

 lawn. The spiders proved themselves competent to meet the 

 emergency. Their first movement 

 was to station themselves beneath 

 the branches of the pine, and in the course 4 



\\>k 



Adapta- 

 tions of 

 Nesting' 

 Habit. 



of time they chose themselves a site at the -j^^^^'i^ ^W^jv^, 

 points where several twigs united. It was ^v ' ^- '■^" ■ '^^' 



impossible, of course, to treat the situa- 

 tion after the fashion to which they were 

 bred among the clumps of huckleberry and 

 sumac bushes, or in the grove of young 

 oaks. The needle like leaves of the pine 

 would permit of no such treatment, but it 

 was not long before the upholstering art of 

 the spider had overcome the difficulty, lashed fig. 273. Adapted Nest of insular spider 

 the prickly leaves into some respectable sem- 

 blance of smoothness, and covered them all over with silken tapestry. 

 Finally, a hemispherical nest was placed within the joints, partly pro- 

 tected on three sides by the twigs, and at the exposed points spun of such 

 close tissues that it formed ample protection. In this particular the pli- 

 alnlity of the spider's architectural instinct was fully demonstrated. 



I have repeated the experiment many times, and always found that 

 these two nest making species when transferred from one plant to another, 

 no matter how different the foliage may be, as in the above cases, are able 

 completely to adapt themselves to the new circumstances and spin a habit- 

 able home. (Fig. 273.) 



In the Domicile spider the habit of leaf tenting is not quite so firmly 



fixed as in the above species. She often builds a leaf nest which does 



not differ from those of her congeners already described, but I 



~ . , have frequently found lier without any such domicile. In Wood- 



laml Cemetery (Philadelphia) are great numbers of this species, 



who find a favorite web site in the interspaces of a barbed iron fence. Very 



