origin of the domestic duck, i. 277;
fertility of the hook-billed duck, ibid.;
occurrence of the plumage of the wild duck in domestic breeds, i. 280;
voice of ducks, i. 281;
occurrence of a short upper mandible in crosses of hook-billed and common ducks, i. 281;
reversion in ducks produced by crossing, ii. [40];
variation of the canary-bird, i. 295;
fashion in the canary, ii. [240];
hybrids of canary and finches, ii. [45].
Brickell, on raising nectarines from seed, i. 340;