24 The Bird 



socket. This growth continuing, the down is hfted clear 

 of the skin, being supported on the new structure, and 



Fig. 12. — Early stages in the development of a down feather, showing close 

 resemblance to scale of fish or reptile. 



Fig. I2a. — Later stages of Fig. 12, showing the first splitting up of the 



feather pulp. 



soon brushed off and lost. Thus, little by little, in 

 shreds and tatters, the bab}' plumage is shed and replaced 



