It has been observed that birds always moult at the time when their food is most abundant; the forest birds may then be seen approaching fields and cultivated places, where, having plenty of insects and seeds, they cannot suffer from want; indeed, the loss of their feathers prevents their taking long flights, and the reproduction of them occasions a loss of flesh which must be repaired. An abundance of food is therefore necessary, and, following this rule, during moulting some additional food must be given to house birds, appropriate to the different species--millet or canary seed, a little hemp-seed, white bread soaked in water, and lettuce, or endive, to those which feed on seeds; with a few more meal worms and ants' eggs to those that eat insects: all should have bread soaked in boiled milk, warmth, and baths. Nothing has succeeded better than this regimen: all the birds which I have seen treated in this manner have passed their moulting season in good health. GIDDINESS. This, without being properly a disease, is rather common, and is occasioned by the trick which the birds of the first class have, of turning their head and neck so far round that they fall head over heels. They may be easily cured of this trick by throwing a covering over the top of the cage, which prevents their seeing anything above them, for it is with looking up that this _giddiness_ comes on. PAIRING FEVER. A disease which may be called the _pairing fever_ must not be forgotten here. House birds are usually attacked with it in May, a time when the inclination to pair is greatest. They cease to sing, become sorrowful and thin, ruffle their feathers, and die. This fever generally first seizes those which are confined in cages: it appears to arise from their way of life, which is too uniform and wearying. I cured several by merely placing them in the window, where they are soon so much refreshed that they forget their grief, their desire for liberty or for pairing, and resume their liveliness and song. I have observed that a single female in the room is sufficient to cause this disease to all the males of the same family, though of different species. Removing the female will cure them directly. The males and females at this season must be separated, so that they cannot see or hear one another. This perhaps is the reason that a male, when put in the window, is soon cured. AGE OF TAME BIRDS.