FEATHER LICE 1 55 



left wing. There is also symmetry in the position of the two holes on the 

 opposite wings. Thus, in one curlew examined, the hole in the seventh 

 primary on each side was 51 millimetres from the base, in the eighth 

 primary 57, in the ninth 54, and in the tenth 57 millimetres. Some of 

 the feathers may have more than one hole. The louse can hardly be 

 credited with the human passion for symmetry, nor is it at all likely that 

 specimens on one side of the bird know what transpires on the other. 

 The answer is most probably that there is a correlation in moulting 

 time between the two wings and that the louse attacks the feather at the 

 earhest moment after its maturity and at the easiest place for boring 

 the hole. The Mallophaga seem to feed on the feather caps left by the 

 withdrawing papilla. The eggs, as in the case of the quill mite, are laid 

 in spiral curves within the shaft; the young develop within the quill and 

 again like the mite leave the quill before the moult is due. A great deal 

 more information on the biology of this louse is needed, including such 

 details as the condition both of the feathers attacked and those not 

 utihsed, and the time of year when the unhatched eggs and nymph al 

 stages are found within the shafts. Anyone who has the opportunity of 

 handling a dead curlew should look out for such points and record 

 them. This louse has been taken from the wings of the curlew, both in 

 this country and America, but from no other wader; all birds, especially 

 waders, should be examined for the minute holes on the shafts of the 

 primaries and secondaries which are made by the quill lice. 



The head lice of three of the British terns are a good illustration of 

 the frequent correlation found between louse size and host size. The 

 smallest louse is found on the little tern, the largest on the sandwich tern 

 and a louse intermediate in size on the intermediate sized host, the 

 common tern. What accounts for this correlation in size ? There 

 may be a close relationship between size of feather parts and size of 

 bird, and this might directly affect the dimensions of the louse. At the 

 present time Httle is known about the differences in feather structure of 

 related species of birds. 



Ralliformes 



Genera of Mallophaga recorded in Britain Pseudomenopon 



(Amblycera); Rallicola, Incidifrons, Fulicqffula (Ischnocera). 



The British rails may be parasitised by three or four species of lice. 

 The large Eulaemobothrion has never been found on any of the British 



