THE FALSE-SCORPIONS OF SCOTLAND 25 



In the former situation, after the stones have been turned up, it 

 gives an observer abundant opportunity of watching it ; when 

 disturbed it draws back its pedipalps to the sides of its fore-body 

 and runs backwards, and it may repeat this backward run several 

 times before it loses fear of danger and begins its forward advance 

 with outstretched pedipalps and open pincers. In the latter 

 situation, however, it moves so rapidly that the observer is more 

 eager to catch it than to watch its actions. 



The only prey which I have seen O. muscorum carrying has 

 been two species of springtail. 



Its nest-building habits are by far the most interesting, and, 

 being somewhat easily investigated, they prompt us to correct lines 

 of observation in other species. The nest of O. muscorum in its 

 finished state resembles a blob of earth or sand corresponding 

 closely with the surface on which it rests. The favourite site is on 

 the under side of a stone, but other localities such as a piece of 

 bark, the face of a rock covered with sheltering herbage, or a 

 compact bed of moss growing on a tree stump may be chosen. 

 At Crieff I once found on the white inner surface of a piece of 

 rotten fir-wood lying on the ground a nest formed of tiny granules 

 of rotten wood harmonising most beautifully with its surroundings. 

 But, wherever placed, the nest harmonises so well with the adjacent 

 material that to the uninitiated it resembles merely a piece of dirt 

 accidentally lying where it is. This wonderful harmony arises 

 naturally from the method employed in the construction of the nest. 

 When the female chooses the site of her future home, under a stone 

 let us say, she forms on the surface of the stone a little domed arch 

 about four millimetres in diameter out of the particles of earth 

 and sand on which the stone is resting. She gathers the particles 

 in a moist condition and attaches them together so carefully that 

 even at this stage the nest is quite firm, and practically impervious ; 

 the inner surface is also beautifully smooth. After some days she 

 spins on the inner side of the dome and over the enclosed surface 

 of the stone, a close firm lining of the finest silk, which renders the 

 whole structure compact and durable, and probably keeps it dry. 

 When on a stone the dome-shaped roof of the nest is complete and 

 free from attachment to any other object ; but in cases where the 

 nest is placed between close-fitting flakes of bark on a tree it may 

 be attached above as well as below, that is to say to the two flakes 

 between which it is placed ; in such cases the built part of the nest 

 consists merely of a very narrow ring of earth and rotten wood, 

 within which, as well as on the two surfaces of bark to which it is 

 attached, is the white silk lining. 



Nest-building for the purposes of reproduction begins in February, 

 but is not in full swing till March, and new nests rarely contain any 

 traces of silk either on the inner surface of the dome or on the 



