At intervals during his life-time Flower communicated a considerable number of letters to the _Times_ and other journals on topics more or less intimately connected with animals and animal life. His sympathy with the crusade against the tight bearing-rein, initiated by his father, has already received mention. Equally marked was his sympathy with the movement against the wearing by ladies of the plumage of birds (other than game-birds, etc.), and more especially the so-called “osprey plumes”—really the breeding-plumes of the egrets and white herons—in the so-called decoration of their bonnets and hats. The extreme cruelty involved—at least in the case of the “ospreys”—in this practice, which entails the destruction of the birds during the nesting-season, when these nuptial plumes are alone donned, and consequently in many instances the destruction of the helpless young by slow starvation, was painted in forcible language by more than one letter from Flower’s pen. Happily, as the result of these and other letters from sympathetic naturalists, and the foundation of the Society for the Protection of Birds (whose general aims were likewise strongly advocated by Sir William), this detestable practice has been much diminished of late years, although very much remains to be done in this way before there can be any pretence of saying that birds, even in this country, are treated by man as they deserve. On another occasion he wrote, deprecating the wholesale destruction of bottle-nosed whales, which had been advocated on account of the enormous quantities of fishes devoured by these cetaceans. The question of pelagic sealing in Bering Sea, and the best way of preventing unnecessary slaughter, and thus eventual extermination, of the sea-bears and sea-lions which visit the Pribiloff Islands, also occupied his attention. And to him was confided the duty of selecting the naturalists (Professor d’Arcy Thompson and Captain Barrett-Hamilton) who represented British interests in the International Commission despatched to those islands in 1896 and 1897, to report on the sealing generally and the habits of the sea-bears, or fur-seals. The best mode of disposing of the bodies of the dead was also a subject to which Sir William devoted a share of his attention, and he was a strong advocate for cremation, or, failing this, for burial in wicker caskets in light sandy soil. The effects of the weather on “Cleopatra’s Needle” a comparatively short time after it had been set up on the Thames Embankment; the best means of utilising and beautifying the gardens in Lincoln’s Inn Fields; and the anomaly that while a heavy book could be sent by post for a few pence, the charge on a heavy letter, at the time in question, was considerable, were among many other miscellaneous topics upon which he wrote.