FEATHER LICE 121 



played by these bacteria is unknown, but it has been suggested that they 

 are in some way associated with the digestion of the specialised diet of 

 the feather Uce. Among the bird Mallophaga, these are found chiefly 

 in the superfamily Ischnocera, which are mainly feather-eaters, and 

 only rarely in the superfamily Amblycera which take blood and other 

 substances in addition to feathers. This fact actually makes the problem 

 more confusing as similar bacteria are found in the sucking lice (Ano- 

 plura), the bed-bugs {Cimex), the fleas (Aphaniptera), the ticks and 

 certain mites (Acarina) which are all true blood-suckers. It has been 

 shown, for instance, that nymphs of the sucking louse of man (Pediculus 

 humanus) cannot survive if deprived of their bacteria. 



Some Mallophaga (of the superfamily Amblycera) may live entirely 

 on blood and serum, or add this to a mainly feather diet. One of the 

 chicken lice (Menacanthus stramineus) , which hves on a mixed feather and 

 blood diet, uses its mandibles to puncture the young feathers in quill and 

 to take the blood from the central pulp supplying the growing feather. 

 Its oesophagus is provided with strong muscles and can exert a sucking 

 action. This species also gets blood by gnawing through the skin of its host. 



The members of one genus of Mallophaga {Piagetiella) Hve attached 

 to the inner walls of the throat pouches of pelicans and cormorants, 

 where their diet must consist of blood and serum, and possibly epidermal 

 debris taken from the walls of the pouch. Another species {Actornitho- 

 philus patellatus) spends part of its life-cycle inside the shaft of the flight 

 feathers of the curlew (Plate lb), probably feeding on the dried feather 

 core. The nymphal stages of one of the species [Dennyus truncatus) found 

 on the swift are said to live on the liquid secretions of the eye of the 

 host. It is doubtful whether any species subsist entirely on epidermal 

 scales and other debris found on the surface of the body of their host, 

 but it is probable that some species, in addition to their normal diet, do 

 undertake a certain amount of general scavenging. In the crop of one 

 louse which he examined Waterston found granules of mica and quartz 

 a butterfly scale, part of a seed coat, a minute fungus, its spore and a 

 fragment of feather. Crops have also been found containing empty 

 Mallophagan ^gg shells, cast larval skins and parts of mites and other 

 lice — this suggests that the Mallophaga may, at times, indulge in 

 cannibalism. 



Locomotion and Sense Organs, Feather lice, as would be expected from 

 the diversity of their body form, show considerable variation in the 



