Sram 
Reproduction 103 
no careful description has been given of natal down. This 
down, in the case of the Larks, is unusually heavy and so serves 
as a protection against the sun from which they are rarely 
Shielded and of a color that has remarkable concealing value. 
The color of the down is cream-buff (from Ridgway’s, 1912, 
“Color Standards and Nomenclature”) and is distributed in 
the following tracts: a double patch (i. e. one on either side), 
on the crown, a double tuft on the occiput, a strip along the 
Figure 13 
a 
3 2 3 4 6 6 7 8 r) 10 
Fig. 13. Growth in weight of a May set of Prairie se hac 
hestlings (nest C;, May 6 to 15, inclusive, Ithaca, NN: Y,, 19 di 
humerus, a strip along the arm, at the tips of the greater coverts 
of the secondaries, a strip on either side of the spinal column 
from below the wings to the tail, and, lastly, a femoral tuft. 
The development of feathers depends entirely upon growth 
in weight, that is, upon amount of food. The deseriptions here 
will be of a normal or optimum development. On the third day 
Pterylae were mapped out on the side of the breast and abdomen, 
in small close-set whitish dots. Pterylae in fine quill tips 
