Page:Supplement to harvesting ants and trap-door spiders (IA supplementtoharv00mogg).pdf/55

 and G represent on a reduced scale five types of wafer nest constructed by as many distinct spiders, and where a gradation may readily be traced between the simplest type at C and the most complicated at G; but we shall speak more fully of this matter by-and-by.

In these diagrams I have placed that representing the nest of Atypus on the extreme left (A); next to this stands that of a nest of the cork type (B), a type which must be carefully distinguished from all the rest. It must not be supposed that the solid cork door (so called from its resemblance to a short cork closing the neck of a bottle), is nothing more than a thicker edition of the wafer door; it is not so, but, on the contrary, possesses a very characteristic structure of its own, being composed of many layers of silk, each furnished with a sloping rim of earth, while the wafer door consists of but a single layer of silk.

I have represented at B 1 the 14 layers of silk and earth which went to make a single cork door examined by me. It will be seen that the outermost of these layers is the largest, and the innermost the smallest, and I have already (Ants and Spiders, p. 150) shown reason for believing that the latter constituted