Concord, Mass.
1910.
April 18
(No 10)
[April 18, 1910]

Bitterns

  On reaching home, late this afternoon, I
at once examined all the Bitterns in my
collection. Most of them unfortunately are
females or males killed in autumn, none
of which have white or whitish anywhere save
on the throats. But two or three adult males
taken in spring posses [possess] tufts of yellowish
white feathers of peculiar & apparently somewhat specialized 
structures which are attached to the sides of
the breast just under the shoulders. By erecting &
spreading these I have been able to produce
something resembling what we saw at Concord
only very much smaller and not pure white,
Gilbert, who has just looked at them, agrees 
with me that the Concord birds (he saw
them showing again on the morning of the 19th)