NEST STUDY OF MARYLAND YELLOW-THROAT 9 
feedings becoming more frequent as the time passes it would 
seem that the former might be true. 
The nest was inspected carefully every few minutes, usually 
by the female, and any foreign substance disposed of. Early in 
the nestling period she seemed dissatisfied with the interior, and 
would pick into it vigorously, sometimes nearly standing on her 
head in her efforts. The observer wondered if this behavior 
could be for the purpose of securing ventilation. Bits of paper 
put in the nest by the observer were carried away on the next 
visit. The nest throughout the period was kept in an immacu- 
late condition. 
REMOVAL OF THE ADDLED EGG 
When the Cowbird’s egg hatched a large fragment of the 
shell fell over one of the Yellow-throat’s eggs in such a way as 
to fit it very exactly ; and as the albumen became dry it became 
securely adhered. In size the fragment was equivalent, per- 
haps, to one third the surface area of the Yellow-throat’s egg. 
The result of this accident was that the latter egg did not hatch, 
but remained in the nest until July 12 (the fifth day). Toward 
noon of this day the foliage overhead had been parted to admit 
the light for photographic purposes. The nestlings had crept 
to one side of the nest to escape the rays of the sun, so that the 
addled egg remained alone and in plain view. The male Yellow- 
throat came first to the nest with food. Seeing the addled egg, 
he picked it up between the mandibles and carried it away, 
without breaking it and with no slips or unsuccessful trials. 
The bird, carrying the egg, disappeared in the foliage of the 
trees at a distance of about twenty-five feet from the nest.* It 
is possible that the ridge formed by the shell fragment may have 
furnished a ‘‘grip’’ by which the egg was firmly held in the 
mandibles. On the other hand, the mandibles are capable of 
opening to a surprising degree, and the whole behavior of the 
bird in this act seemed to proceed without uncertainty or experi- 
mentation. 
*The | description of the removal of the egg is given by Dr. Stephens, who 
occupied the blind at the time of its occurrence. 
