FITTING TO CONDITIONS.

Star (Christchurch), Issue 12786, 1 November 1919, Page 5

FITTING TO CONDITIONS.

PECULIAR ADAPTATIONS OF ANIMALS. Every one of the higher animals is in some way mechanically adapted to its mode of life and surroundings a horse or an antelope being from one point of view a living galloping or trotting machine. Putting such examples aside, there are numerous cases of more peculiar adaptations to whiijh attention may be confined. For example, the climbing creatures. It may be noted that a number of species, such as Old World monkeys and squirrels, present special modifications for a life in the trees, the essential being that they should have tbs power of rotating the forearm on the upper portion of tho limb and that their toes should be mobile and furnished with claws or nails. There is one group of African rodents, designated scaly tailed squirrels, the members of which seem to have felt ■ the necessity of additional aid for the purpose of tree climbing. They have accordingly developed ou the under surface of tho tail certain structures which ; be compared to the climbing irons used by workmen. These take the form of a few transverse rows of large, triangular, horny scales, with their points directed backward. These scales, when pressed against the hark of a tree, must afford material aid in climbing. THE ANTBATEIPS CLIMBING (SCALES. Another group of animals in which ■‘climbing irons” have been developed is that of the scaly anteaters, or pangolins. of India and Asia—creatures which look more like living fir cones than mammals. The scales—much larger than those «*» the scaly tailed squirrels—cover both surfaces of the body, as well as the head and limbs, so that it can scarcely bo supposed they have been developed for climbing. Indeed, only a few species climb; but these have found tho assistance afforded by the scales on tho under side of value in an ascent, and habitually make use of them as climbing irons. Quite a- different type of climbing, or rather banging, apparatus has been ’cveloped in tho sloths of tropical Ame--1 rica, which spend their time in tho I treetons, where they remain suspended back downward by their hook-like claws. These claws, which may be three or two. have been modified from ordinary claws and afford a striking instance of adaptation to an abnormal mode of j life. I The thumb of bats is likewise modified into a hook-liko claw—also used for suspending purposes when the creatures hang head upward. Generally, however, bats suspend themselves head downward by tho bind claws, grasping power being retained by the toes, so that the modification has not been carried to tho same extent as in sloths, _ iu which tho daws set in a mechanical manner. SUCTION PLATES ON BATS. Certain bats appear to liave found their hook-like thumbs and bind feet insufficient for suspension, and Lave made uso of tho suction principle for this purpose. This mode of suspension has been developed independently in two distinct bats, one a native of Brazil and tho other of Madagascar. In tho Brazilian species tho suckers take tlio form of stalked discs attached to tho palms of tho tint mbs and the soles of tho feet. The suckers of the Malagasy species arc horseshoe like. By .means of the suckers there bats are able to ascend vertical surfaces. Very curious it is to no to i the similarity between tho suckers of Ihcse bats and thoso on tho amis of the cuttlefishes. Tho geckos which run up tho walls and over tho ceilings of houses in wlaim omuitries (afford another in-( atanco of the sucker principle. Bats are not tho only mammals which have availed themscivo? of tho sucker. Iu tho Malay Islands and - the i’hilippines dwell large-eyed and slender-limbod little lomur-liko creatures known us tarsiers, whose habits are nocturnal. In these woiid little animals the tips of the toes are expanded into cushionliko discs, capable of acting as 'suckers, by means of u Inch they ascend such smooth surfaces as tho stews of 1 bamboos. Hoofed or ungulate animals, such as sheep, pigs, camels and elephants, have given up using their fore limbi in a nanyliko manner, and employ j them solmv for progression. Consequently tree climbing is out of their line. In Africa and Syria occur, however, certain representatives or the order known ns rock rabbits, or hyrax, the Syrian species being the one referred to in the Bible as the coney (the old name of the rabbit.) Certain African hyraxes have, however, taken to tree climbing, and tho way they manage it is this: lu each foot the solo is somewhat cup-shaped, and by tho aid of muscular action the centre can bo bo more derated, so that when the edges a,ro applied to the bark tho foot acts like a sucker.