206 
FRANCIS H. HERRTCK 
of the sixth day the horny sheaths of many of the quills begin 
to give way at their base, and are raked off by the mouthful, thus 
at one stroke exposing a few of the contour-feathers, which 
quickly fluff out to their normal proportions. In course of time 
these empty tubes come to litter the nest, and can be seen on the 
ground beneath it (fig. 21, r). Yet for this partly fledged bird, 
with senses becoming hourly more acute, its shallow platform 
of a nest is still for a time surrounded by an invisible wall, and 
no amount of heat or discomfort can drive it out. If handled at 
this time the scales and feather sheaths fall from it like ashes 
from a cigar. 
To one who has not watched the course of events daily and 
hourly, this emergence of the true feathers seems both more sud- 
den and more complete than it really is. Where before you saw 
a bird bristling wdth quills, after the lapse of twelve hours you 
find one clothed in soft feathers. The change is certainly strik- 
ing, but it is neither sudden nor complete. As is well known, the 
feather-tubes of altricious birds commonly break away slowly 
from apex to base, in fine powdery scales, and the contour-feather 
is gradually exposed, passing from the tube or pin-feather, to the 
'paint-brush' stage, and so on until the whole vane is clear. This 
is also true in some degree of the cuckoo, for at the climbing stage 
the tail and wing-feathers of flight are exposed only at the tips, 
their horny sheaths breaking away centripetally precisely as in 
other birds (fig. 21, i-m). At this time the primaries are freed 
for about one-half their length (figs. 4 and 8). This is also true 
of most of the feathers of the back (dorsal tracts) , while many of 
the tubes of the head and throat, which are inaccessible to the 
'comb,' are still intact. The sheaths are removed completely 
and entire only from the breast and sides (fig. 21, r). 
Dugmore,2«5 who was I believe the first to describe the apparently 
sudden emergence of the feathers in the yellow-billed cuckoo, says 
in one place that ''The young when hatched are entirely naked," 
and in another, that the young which had been hatched in an in- 
terval of three days since he had seen their nest, were "naked 
- 26 Dugmore, A. Radcliffe. Bird-homes, pp. 6, 135. New York, 1900. 
