NATURAL SCIENCES OF PHILADELPHIA. 293 



bark of the chestnut, plucked, doubtless, from fence rails, and 

 reduced to very fine strips for the inner part of the nest, and 

 gradually attaining a width of nearly one-fourth of an inch on 

 the exterior. 



In an intermediate form between the ordinary form and the first 

 deviation therefrom, I find the diameter 4^ in. externally', depth 

 2 in. ; cavity 2^ in., and depth 1^ in.; lateral walls each 1 in. ; in- 

 ferior ^ in. This nest is formed of fine grasses, hair, wool, and 

 an abundance of moss externally ; within it is lined by fine grasses 

 and hairs ; the absence of clay would seem to impl}' an unexposed 

 place for its site, to which theory the looseness of its structure 

 most assuredly adds weight. 



That a species which has always been known to build a nest 

 so characteristic as the pewee should deviate so considerably, 

 and suddenly, as it seems to be, from its ordinary habit 

 of nest-building, is remarkable. But such is the fact, as the 

 mother-bird was discovered in the act of incubation. It has been 

 suggested that possibly these nests were stolen propert}^, and not 

 the work of the bird in question. But this I am satisfied is not 

 the case. The individuals of some species do take forcible pos- 

 session of the abodes of others, or the cavities in which such are 

 secreted, but I have never known the intruders to occupy the 

 same, except in the case of Molothrus pecoris, Seo., of America, 

 and Cuculus canorus of England. As these birds never build, 

 but deposit their eggs in the nests of other birds, I am hardly 

 disposed to grant the propriety of considering them in this 

 light. It is well known that Troglodytes sedon, of Yerrill, does, 

 when prompted by a mischievous spirit, drive away Icterus Balti- 

 more, Daud., and Sayornis fuscus, Baird, from their rightful pro- 

 pert}^, and take up her abode therein, but not without having 

 previously constructed her rude nest of coarse sticks, well lined 

 with feathers and down. 



So strong is the attachment of birds to the nests of their own 

 construction, that the parental instinct is often lost sight of. 

 Proofs could be cited to sustain this assertion. One, however, 

 will suffice. Two years ago in Atlantic County, New Jersey, I 

 came across a nest of the robin, which on account of its curious 

 arrangement, I desired to possess. Unable to wait until the un- 

 fledged brood had taken their departure, I conceived the plan of 

 remoA'ing them to another nest of the same species, not so neatly 



