SPIDERS 319 



opaque bar right across the diameter of the web, or at 

 others a zig-zag between two of the radii only. The 

 reason for this is obscure ; I can only suggest that it 

 is analogous to the trapper's artifice of putting an object 

 across the track of some animal which, making a detour 

 to avoid what it imagines to be a trap, falls into the real 

 trap set at' the side. An insect on the wing, supposedly, 

 sees the conspicuous part of the web, takes care to fly 

 past the side of it, and is caught in the inconspicuous 

 part which it has not seen. 



On an earlier page attention was directed to silver 

 markings on insects ; a spider found on Dwaji Isle in 

 1919 was notable. It was of fair size and spun its web 

 among heads of dry grass ; the colour of the cephalo -thorax 

 and front part of the abdomen was pure silver, the rest 

 of the abdomen was dark, but speckled with yellow and 

 with a series of silver bands ; the legs were banded alter- 

 nately dark and speckled-yellow. 



Of the smaller members of Arachnida, Ticks call for 

 notice, but only on account of their great scarcity on 

 the islands. This is presumably associated with the 

 absence of cattle and all buck except the Situtunga ; 

 and if the islands could be again inhabited it should be 

 possible to keep cattle there free from ticks and therefore 

 from the diseases carried by them. 



The Varanus often has numbers of ticks on it, but 

 these are not of the species which feed on cattle ; 

 prettily decorated ticks ^ have also been found on the 

 Horned Puff Adder. The islands are also singularly 

 blest in the absence of Scorpions, which were not met 

 with ; possibly the climate is too continuously humid 

 for them. 



The great group of Myriapoda calls for passing 

 notice, firstly because of the absence of the huge 

 centipedes found in some parts of Africa, and secondly 



^ Aponomma Iceve. 



