—90— 



of the glass and attached in small lumps at b; c, represents the nest, a 

 small tower against the glass. Fig. 12, was made by No. 26. This is 

 interesting as being the only one showing the concentric "lines of growth" 

 usually noticed in the doors of nests that have been used for a year or so. 

 No. 14, first dug a shallow hole as represented at b, fig. 13; abandoning 

 this it dug another at c; it then removed the earth at d, making a trench: 

 next it began the tube at c. but soon abandoned it, began again at /', 

 restored d, and completed the nest in the normal way. The following 

 table shows the varying positions of the door when closed. 



Horizontal: Nos. 1, 2, 4, 5, 6, 9, 10, II, 12, 14, 16, iS, 19, 20, 21, 



23, 27, 28. 



Sloping downward from hinge attachment: Nos. 3, 7,8, 15, 17, 



22, 24, 26. 



Rising from hinge attachment: No. 13. 

 Sloping door with hinge at one side: No. 25. 

 Table showing the kinds of nests. 

 Curved tube: Nos. 3, 8, 25. 

 Straight tube: Nos- 1, 2, 4, 5- 6 > 9> io . lI > I2 > I 3» H, 16, 18, 19. 



20, 21, 23, 24, 25, 27, 28. 



Trench with arched walls: Nos. 7, 15, 17, 22. 



Nests of mature spiders, of this species, made in captivity present 

 some of the variations mentioned above, as also some of the nests found 

 in a state of nature. 



One of the most interesting things which came under my observa- 

 tion during the work of these spiders was the varying potency of instinct 

 manifested in the aptness with which each performed the task of building 

 its home. This will be best illustrated by giving a few of the more 

 striking examples recorded in my notes. No. 6, was placed in the bot- 

 tle at 10.30 p. m. and began digging the tube in the noimal way at 1 1. 1 5 

 p. m. It worked rapidly, sometimes taking up and unloading a pellet of 

 earth in 10 seconds. Indeed it worked with as much ease, accuracy, and 

 apparent thoughtfulness, as the mature one which I have described in 

 the Amer. Nat. Sometimes with its palpi it would flirt the pellet across 

 to the opposite side of the bottle. It began making the trap-door at 

 12.30 a. m. and completed it at 1 a. m; one hour and forty-minutes 

 from the time it began work, and two hours and thirty minutes from the 

 time it was placed in the bottle.* During the operation every movement 

 seemed to facilitate the work. No. 19, was placed in the bottle at 6.30 

 p.m. : my notes read as follows: — "Began digging tube in normal way at 

 7.50. Does not seem to be satisfied with work, and begins in another 

 * One completed the work i = hour and 30 minutes; and another 1 hour and 20 m. 



