128 POULTRY DISEASES AND THKIR TREATMENT. 



"Life-history of Lice. — All the lice breed fairly rapidly. The 

 eggs or nits are laid upon the down feathers, as a rule ; they are 

 often beautifully sculptured objects, oval in fonu. In about 6 

 to lO 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. 24) has been kept alive for 

 months upon fresh feathers, the quill epidermis being especially 

 eaten. Before reaching the full-grown state as many as 10 or 

 12 moults 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. 27. 



Fig. 27. Feathers showing eggs or "nits" of the common hen louse. 

 Enlarged (Original ) . 



Methods of Introduction and Infestation. — It is generally 

 agreed that lice and other parasites flourish best in insanitary 

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

 tion. Lice are brought to a new place by introducing infested 

 birds. They spread from bird to bird (a) directly during copu- 

 lation (an infested cock often infests the whole flock), or (b) 

 when two hens occupy a nest together, or (c) from mother to 

 chick. They also pass indirectly from bird to bird by crawling 

 off one bird first on to the nesting material and later on to an- 

 other bird which uses the same nest. Doctor Sharp has also 



