i. 306, 307;

on the coloration of the _Triphaenae_, i. 395; on the rejection of certain caterpillars by birds, i. 417; on sexual differences of the beak in the goldfinch, ii. 40; on a piping bullfinch, ii. 52; on the object of the nightingale's song, ii. 52; on song-birds, ii. 53; on the pugnacity of male fine-plumaged birds, ii. 93; on the courtship of birds, ii. 94; on the finding of new mates by Peregrine-falcons and Kestrels,