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Bird -Lore 



effect of wear is shown by photomicrographs of brown Purple Finch feathers, 

 and the second is shown by the figures of Crossbill feathers. We have 

 illustrated also the effect of wear on a Meadow Lark, showing how the 

 lighter-colored parts of feathers may disintegrate. 



The growth of each feather is a chapter by itself. The histologist 

 with microscope and cross -sections tells us how beneath the old feather, 

 resting in a pit or follicle of the skin, certain cells group themselves and 

 multiply until a papilla or feather germ is formed. This pushes out the 



Fresh feather Worn feather 



PHOTOMICROGRAPHS OF CROSSBILL FEATHERS 



old feather and lengthens into a pulpy cylinder from the apex of which 

 the 'pin-feather' expands, being built by the pulp cells from the tip 

 downward and from the edges inward as the papilla elongates. This is 

 but a rude way of expressing the very elaborate process of feather-growth 

 completed when, in the course of a few weeks, the pulp of the calamus, 

 or quill-part of the feather, dries up. Each papilla produces a new 

 feather at the time of a molt (and also whenever one is accidentally 

 pulled out) and enjoys a period of rest between times. The individual 

 feathers of the natal plumage, technically known as neossoptiles, are ex- 

 ceptions and are continuous in growth with the tips of the feathers of 

 the Juvenal plumage. 



A molting bird is as confusing to examine as any prize puzzle, but series 



