The Beauties of Nature, and the Wonders of the World We Live In. Sir John Lubbock

bones, but every ridge and surface for the attachment of muscles, and every hole for the passage of artery or nerve, seen in the one can be traced in the other." It is often said that the Horse presents a remarkable peculiarity in that the canine teeth grow but once. There are, however, in most Horses certain spicules or minute points which are shed before the appearance of the permanent canines, and which are probably the last remnants of the true milk canines.

      The foot is reduced to a single toe, representing the third digit, but the second and fourth, though rudimentary, are represented by the splint bones; while the foot also contains traces of several muscles, originally belonging to the toes which have now disappeared, and which "linger as it were behind, with new relations and uses, sometimes in a reduced, and almost, if not quite, functionless condition." Even Man himself presents traces of gill-openings, and indications of other organs which are fully developed in lower animals.

      MODIFICATIONS

      There is in New Zealand a form of Crow (Hura), in which the female has undergone a very curious modification. It is the only case I know, in which the bill is differently shaped in the two sexes. The bird has taken on the habits of a Woodpecker, and the stout crow-like bill of the cock-bird is admirably adapted to tap trees, and if they sound hollow, to dig down to the burrow of the Insect; but it lacks the horny-pointed tip of the tongue, which in the true Woodpecker is provided with recurved hairs, thus enabling that bird to pierce the grub and draw it out. In the Hura, however, the bill of the hen-bird has become much elongated and slightly curved, and when the cock has dug down to the burrow, the hen inserts her long bill and draws out the grub, which they then divide between them: a very pretty illustration of the wife as helpmate to the husband.

      It was indeed until lately the general opinion that animals and plants came into existence just as we now see them. We took pleasure in their beauty; their adaptation to their habits and mode of life in many cases could not be overlooked or misunderstood. Nevertheless the book of Nature was like some missal richly illuminated, but written in an unknown tongue. The graceful forms of the letters, the beauty of the colouring, excited our wonder and admiration; but of the true meaning little was known to us; indeed we scarcely realised that there was any meaning to decipher. Now glimpses of the truth are gradually revealing themselves, we perceive that there is a reason, and in many cases we know what the reason is, for every difference in form, in size, and in colour; for every bone and every feather, almost for every hair.[12]

      COLOUR

      The colours of animals, generally, I believe, serve as a protection. In some, however, they probably render them more attractive to their mates, of which the Peacock is one of the most remarkable illustrations.

      In richness of colour birds and insects vie even with flowers. "One fine red admiral butterfly," says Jefferies,[13] "whose broad wings, stretched out like fans, looked simply splendid floating round and round the willows which marked the margin of a dry pool. His blue markings were really blue—blue velvet—his red and the white stroke shone as if sunbeams were in his wings. I wish there were more of these butterflies; in summer, dry summer, when the flowers seem gone and the grass is not so dear to us, and the leaves are dull with heat, a little colour is so pleasant. To me colour is a sort of food; every spot of colour is a drop of wine to the spirit."

      The varied colours which add so much to the beauty of animals and plants are not only thus a delight to the eye, but afford us also some of the most interesting problems in Natural History. Some probably are not in themselves of any direct advantage. The brilliant mother-of-pearl of certain shells, which during life is completely hidden, the rich colours of some internal organs of animals, are not perhaps of any direct benefit, but are incidental, like the rich and brilliant hues of many minerals and precious stones.

      But although this may be true, I believe that most of these colours are now of some advantage. "The black back and silvery belly of fishes" have been recently referred to by a distinguished naturalist as being obviously of no direct benefit. I should on the contrary have quoted this case as one where the advantage was obvious. The dark back renders the fish less conspicuous to an eye looking down into the water; while the white under-surface makes them less visible from below. The animals of the desert are sand-coloured; those of the Arctic regions are white like snow, especially in winter; and pelagic animals are blue.

      Let us take certain special cases. The Lion, like other desert animals, is sand-coloured; the Tiger which lives in the Jungle has vertical stripes, making him difficult to see among the upright grass; Leopards and the tree-cats are spotted, like rays of light seen through leaves.

      An interesting case is that of the animals living in the Sargasso or gulf-weed of the Atlantic. These creatures—Fish, Crustacea, and Mollusks alike—are characterised by a peculiar colouring, not continuously olive like the Seaweed itself, but blotched with rounded more or less irregular patches of bright, opaque white, so as closely to resemble fronds covered with patches of Flustra or Barnacles.

Take the case of caterpillars, which are especially defenceless, and which as a rule feed on leaves. The smallest and youngest are green, like the leaves on which they live. When they become larger, they are characterised by longitudinal lines, which break up the surface and thus render them less conspicuous. On older and larger ones the lines are diagonal, like the nerves of leaves. Conspicuous caterpillars are generally either nauseous in taste, or protected by hairs.