360 INSECT ARCHITECTURE. 



suspensory lines, — a circumstance alleged to be 

 proved by the former appearing under the micro- 

 scope studded with globules of gum.* We have not 

 been able to verify this distinction, having seen the 

 suspensory lines as often studded in this manner as 

 those in the centre. | 



Mason-Spiders. 



A no less wonderful structure is composed by a 

 sort of spiders, natives of the tropics and the South 

 of Europe, which have been justly called mason- 

 spiders by M. Latreille. One of these (Mijgale 

 nidulans, Walckn.) found in the West Indies, " digs 

 a hole in the earth obliquely downwards, about three 

 inches in length, and one in diameter. This cavity 

 she lines with a tough thick web, which, when taken 

 out, resembles a leathern purse; but what is most 

 curious, this house has a door with hinges, like the 

 operculum of some sea-shells, and herself and family, 

 who tenant this nest, open and shut the door when- 

 ever they pass and repass. This history was told 

 me," says Darwin, '^^ and the nest, with its door, 

 shewn me by the late Dr Butt, of Bath, who was 

 some years physician in Jamaica. "J 



The nest of a mason-spider, similar to this, has 

 been obligingly put into our hands by Mr Riddle, 

 of Blackheath. It came from the West Indies, 

 and is probably that of Latreille's clay-kneader 

 (^Mygale craiicns), and one of the smallest of the 

 genus. It is composed of very hard argillaceous 

 clay, deeply tinged with brown oxide of iron. It is 

 in form of a tube, about one inch in diameter, between 

 six and seven inches long, and slightly bent towards 

 the lower extremity — appearing to have been mined 

 into the clay rather than built. The interior of the 



* Kirby and Spence, Intr. i. 149. t J. R. 



t J^arwin'e Zoonomia, i= 253. 8vo. ed. 



