20 JOURNAL OF THE 



spider had thrown into it from above. After the second 

 night the door appeared nearly of the normal texture and 

 thickness, but in no case would it open completely, and it 

 seemed the spider was too much disgusted with her quarters 

 to think it worth while to make a perfect door.'" 



He also records the making of a door by a very young 

 one of this species, in which the threads, except at the hinge, 

 were cut so that the door would open and shut.* 



The only thing he records which seems at all analagous 

 to the mode of making a trap-door exhibited by the spider 

 in my possession is that manifested in the enlargement of 

 nests and trap-doors by spiders as they grow larger, and 

 consequently require nests of larger dimensions. This ope- 

 ration was not witnessed by him, however, but the additions 

 to the size of the door were proven by measurements and 

 observations upon nests of young spiders at different seasons,'^ 



It would seem natural to suppose that, in making slight 

 additions from time to time to the edge of the nest, the spider 

 would cement pellets of earth, pieces of moss, etc., to the 

 edge, instead of first spinning a web ; unless the web is spun 

 over the lower side of the door and made to project just far 

 enough to fit the enlarged tube. In Plate XXIII, Fig. 8, 

 can be seen eight concentric " lines of growth," as they might 

 be termed, of the trap-door, corresponding to the growth and 

 needs of the spider. These I judge to represent the succes- 

 sive enlargements of the door concomitant with the enlarg- 

 ing of the tube. We can safely say that these additions were 

 made by cementing the material, piece by piece, which forms 

 each ring, to the edge of the door. These " lines of growth " 

 are not present in the door made by the adult spider in cap- 

 tivity. I induced the spider to make the door the fourth 

 time, (Jan. 19, 1886,) in order to observe if there was any 

 regularity in the cementing of the particles, which might 

 form these lines of growth in a door made by an adult spider. 

 There is no such regularity. Indeed his last door was made 

 of about a dozen very large pellets of clay, which, being very 

 plastic, the spider was able to press each pellet into a sheet 

 of considerable dimensions. 



It is to be regretted that Mr. Moggridge did not have the 



'Harvesting Ants and Trap-Door Spiders, p. 118. 

 'Harvesting Ants and Trap-Door Spiders, p. 119. 

 ^Idem. pp. 123. 127 and 150, and Supplement, p. 245. 



