_Light and Colour._--My description of tropical climates is borrowed from a large number of travellers,--Humboldt, Azara, Auguste, Saint-Hilaire, Castelneau, Weddell, Charles Waterton, and others. For Brazil and Guiana, I have been greatly indebted to the exceeding courtesy of M. Ferdinand Denis, whose knowledge of those countries is so perfect. Paris possesses several fine collections of insects, besides that of the Museum. One of the best-known is Doctor Bois Duval's (lepidoptera). An establishment exclusively devoted to the sale of insects may be found at No. 17 Rue des Saints-Pères. The magnificent collection to which I refer on page 176, is that of M. Douë, who most readily showed it to us, and explained it with infinite complaisance. The anecdote which concludes chapter xii. (_The Ornament of Living Flames_) is related, in reference to the women of Santa Cruz in Bolivia, by the always accurate Dr. Weddell. The Indian phrase, "Replace it whence thou borrowedst it," is recorded by Waterton. [Illustration] NOTE 10.--Book ii., Chap. viii. _Renovation of Human Arts by Study of the Insect._--Who has not seen that for a long time the art of decoration has made no progress, does but incessantly repeat itself? When a particular subject has lasted ten years, men think to rejuvenate it with a few variations. In a life of half a century I have several times seen this rotation of fashion, which would appear singularly monotonous if we did not possess in so high a degree the gift of forgetfulness. The decorative art, instead of seeking its renovation in the things of old, would profit greatly by drawing its inspiration from the infinity of beauties distributed throughout Nature. They abound and superabound:-- 1st, In the highly accented forms of tropical plants. Ours only produce their effect in masses, and on a grand scale. 2nd, In those of a great number of the lower animals, radiata, and others; in many of the little floating molluscs, living and imperceptible flowers, the design of which, when enlarged, might suggest some very original ideas. 3rd, In certain parts of the most despised creatures; as, for example, in the eyes of the fly. 4th, In the forms, designs, and colours one detects in the thickness of the living tissue; as, for example, on lifting with the scalpel the strata of the wing-sheath of the beetles. Nature, which has so embellished the surface, has hidden, perhaps, still more beauty in the depth. Nothing is finer than the vital fluids, when seen in the mobility of their circulation, and in the delicate canals where that circulation is accomplished and defined. They speak to us less eloquently, and impress us less forcibly by the splendour of the glittering leaves among which they circulate, than by the expressive forms in which we divine the mystery of their life. These are their visible energies. [Illustration] NOTE 11.--Book ii., Chaps. ix. and x.