126 TRAP- DOOR SPIDERS. 



did SO, no doubt, in their day, for they are exact copies 

 in miniature of the ordinary horse-shoe shaped lower 

 doors. The lower door actually in use may sometimes 

 be found to have two separable cases of thick silk 

 enclosing the central mass of earth, and this also, very 

 probably, represents enlargement. In the nests of JV. 

 meridionals I have never found any of these abandoned 

 doors behind the one in use, nor should I expect 

 to find any, for if they were present they would 

 permanently obstruct the entrance from the main tube 

 to the branch. 



It is clear that it is better economy on the part of 

 the spider to enlarge its nest rather than build a new 

 one each time. If we compare the infant spider and its 

 nest (fig. B, Plate IX., p. 98) with the full-grown 

 creature and its nest (fig. A, Plate IX.), it becomes 

 evident that the growing spider must either construct 

 many nests of intermediate size, or frequently enlarge 

 the original domicile. And we do in fact find nests 

 of all sizes between the two extremes. 



I cannot help thinking that these very small nests, 

 built as they are by minute spiders probably not very 

 long hatched from the egg, must rank among the most 

 marvellous structures of the kind with which we are 

 acquainted. That so young and weak a creature should 

 be able to excavate a tube in the earth many times its 

 own length, and know how to make a perfect miniature 

 of the nest of its parents, seems to be a fact which has 

 scarcely a parallel in nature. 



When we remember how difficult a thing it is for 

 even a trained draughtsman to reduce by eye a com- 

 plicated drawing or model to a greatly diminished 

 scale, we must own that the performance of this feat 



