404 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



after this test was made, late in November, the spider closed its burrow 

 with a canopy of thick web, over which were drawn a few sticks and 

 straws. It cannot be doubted that the advantage thus secured by the bur- 

 rowing habit, against the exigencies of a severe winter, strongly tend to 

 protect the life of Lycosids. 



I have also called attention to the fact, while treating upon the cocooning 

 industry and maternal instincts of spiders, that the industrial product of 

 such skillful architects as certain Lycosids and the Trapdoor spiders, is 

 probably influenced by the mother's wish to protect her eggs. I refer the 

 reader to what is said Chapter III., page 64, merely remarking that it 

 would indeed be strange were not the strongest feelings in animal nature 

 to leave their impress in some form upon the industrial life of animals. 

 I have also suggested that even the sexual excitement of the male reacts 

 upon his industrial energies and tends to the development of a higher skill, 

 at least in certain species. (See page 65.) 



I now proceed to show that the necessity of self protection against their 

 most persistent and formidable enemies, the wasps, has led certain Lycosids 

 to adopt a special and interesting form of protective architecture. 

 4. Self We fortunately have abundant facts in the case of Lycosa tigri- 

 . , ec na, 1 as carefully observed and recorded by Mrs. Mary Treat. 2 

 dustry. Tigrina's method of working, as observed from a large female 

 specimen in confinement, is as follows: She first spins a canopy 

 of web over her tunnel, leaving a place of exit on one side. She next goes 

 out and carefully moves over the canopy as if to see whether it is strong 

 and secure. Satisfied that it is all right, she steps down, just letting her 

 fore feet touch the web, while with her hind legs she feels and apparently 

 examines the material. Finally, she selects a dry oak leaf about two inches 

 broad and three in length, lays it over the canopy, and proceeds to fasten 

 it down all around except at the entrance. After, the leaf is made secure 

 she reaches up and pulls down blades of grass, lays them over the leaf and 

 dexterously fastens them down with webs. This makes a strong roof for 

 her domicile. Then she goes within and puts the finishing touches on the 

 inside. This done, she stands in the door of her neat apartment awaiting 

 insects that may chance to come within her range. If a beetle, 

 Tigrina's f or example, approaches, she rushes upon it and bears it into 

 her den. A few days after the work is thus begun, Tigrina com- 

 pletely closes the entrance to her domicile, and the observer avers 

 that if she had not known the spot in which it was located, she would 

 not have been able to find it. 



1 Tarantula tigrina McCook, Proceedings Amer. Entom. Soc. (Section), page xi., May, 1879. 

 The burrowing habit of this species is there for the first time fully described by me, and a 

 brief description given of the female. Emerton (New England Spiders of the Family Lyco- 

 sidfie, 1885) describes the species as Lycosa vulpina. I judge that my own name has pre- 

 cedence. 2 Home Studies in Nature, Hair's Magazine, 1880, page 710. 



