Except in a few cases, notably the birds, reference to disease has been brief. If sick animals do not respond quickly to the simple household remedies which suggest themselves, a veterinary should be summoned, or the suf ferer destroyed. To attempt to treat a creature that is seriously ill is a task which only a trained person should assume. Bird diseases, however, have received scant atten tion from investigators, and the little space devoted to them here will not be amiss. The question of scientific breeding may seem somewhat erudite for the field indicated by the title of this work. Its importance is so great, however, that a few words, outlining the fundamentals, have been added as an appendix. For those who desire more extensive information than is given here, a list of practical works is given. To many of them I am indebted for reference during the preparation of this volume and hereby make full acknowledgment.