208 Diseases of Poultry 



to 10 days they hatch into small, pale, active lice, which 

 at once commence to irritate the birds. The adults are 

 occasionally found in the nests. Some species are found 

 copulating in the nests, others always on the birds. They 

 live a considerable time. Menopon 'pallidum (Fig. 36) 

 has been kept alive for months upon fresh feathers, the 

 quill epidermis being especially eaten. Before reaching the 



Fig. 39. — Feathers showing eggs or "nits" of the common hen louse. 

 Enlarged. (Original.) 



full-grown state as many as 10 or 12 molts apparently take 

 place, there being little difference in each stage, except the 

 gradual darkening of the markings. 



The eggs or nits of hen lice are shown in Fig. 39. 



Methods of Introduction and Infestation. — It is generally 

 agreed that lice and other parasites flourish best in insanitg,ry 

 surroundings. There must, however, be a source of infesta- 

 tion. Lice are brought to a new place by introducing in- 

 fested birds. They spread from bird to bird (a) directly 

 during copulation (an infested cock often infests the whole 



