104 FALSE-SCORPIONS 



and the species involved are those that inhabit fallen leaves and 

 debris, not those that live under stones and beneath bark (Vachon, 

 1947a). 



The ability of false-scorpions to spin was denied by some of the 

 earlier writers, but it is now known that they construct nests 

 partly or wholly of silk from their own bodies. The animals usually 

 enclose themselves in these nests for moulting, for brood pur- 

 poses and, in some cases, for hibernation. Such nests are closed 

 cells of spun tissue with or without an external cover of extraneous 

 matter. They are roughly circular in shape and may be attached 

 above and below to the solid surfaces of narrow crevices. When 

 they are attached on one side only they have a free, convex roof 

 and may be fixed here and there to surrounding objects. The ex- 

 ternal covering, if present, consists of earth or vegetable fibres 

 which are not bound to the structure but are firmly attached to it, 

 but the interior is smooth and always free from foreign matter. 

 The spun tissue is thin and dense, composed of innumerable 

 threads, crossed and recrossed and coalesced in irregular con- 

 fusion without interspaces. 



The silk is derived from glands in the cephalothorax whose 

 ducts traverse the chelicerae to the apex of the movable finger. 

 They open at the tips of the branches of the galea or on or near 

 the margin of a tubercle which replaces that structure in some 

 groups. The spinning is done with the chelicerae but the presence 

 or absence of the galea does not appear to be associated with 

 differences of method or in the tissue: the serrulae, etc. are not 

 concerned. Nest building is carried out from within. The con- 

 struction of an external framework is the first task, and where this 

 has a coating of extraneous materials, the animal frequently goes 

 out to collect them. They are picked up in the pedipalps, trans- 

 ferred to the chelicerae and attached to the nest by the application 

 of silk to their inner surfaces. The silk is drawn from the galea or 

 tubercle in several viscid and very fine threads which may remain 

 separate or may coalesce, and the spinning is accompanied by 

 continuous forward and backward movements of the body and 

 by lateral movements of the chelicerae. At first, when attachments 

 are being made from place to place, the threads usually do coalesce, 

 but afterwards the animal settles down to long continued spinning 



