occurrence of horns in hornless breeds of sheep, ii. [30];
hybrids of the horse and ass, ii. [68];
crosses of tailless fowls, ii. [92];
difficulty of pairing dove-cot and fancy pigeons, ii. [103];
fertility of tame ferrets and rabbits, ii. [112];
fertility of wild sow, ibid.;
difficulty of breeding caged birds, ii. [154];
comparative fertility of Psittacus erithacus in captivity, ii. [155];
on changes of plumage in captivity, ii. [158];
liability of light-coloured cattle to the attacks of flies, ii. [229];