OCR Text |
Show 92 DARWINIHJ\1 C. HAP. Some EnO'lish tumblers arc almo t equally persistent. A writer, qr~tccl by Mr. Darwin,. <tys th<Lt these birds gcncra11y begin to tumhle almost as soon a. they cn.n fly ; "at three months old they tumble well, but still fly strong; at five or six months they tumble execs ivcly; and in the second yen.r they mo. tly give up flying, on account of their tumbling ·o much and so close to the ground. Some fly roul\(l with the flock, throwing tL clean summersault every few yards till they are obliged to settle from giddiness and cxha.u tion. These arc called Air-tumblers, and they commonly throw from twenty to thirty summcrsa.ults in a minute, each clear and clean. I have one reel cock that I have on two or three occasions timed by my watch, and counted forty snmmcrsaults in the minute. At first they throw a inglc summersault, then it is double, till it becomes a continuous roll, which puts an end to flying, for if they fly a few yards over they go, and roll till they reach the ground. Thus I had one kill herself, and another broke his leg. Mn.ny of them turn over only a few inches from the ground, and will tum hlc two or three times in flying across their loft. These arc calle<l House- tumblers from tumbling in the house. The ~wt of tumbling seems to be one over which they have no control, an involuntary movement which they seem to try to prevent. I have seen a bird sometimes in his struggles fly a ya.nl or two straight upwards, the impulse forcing him backwal'<ls while he struggles to go forwards." 1 The Short-faced tumblers are an improved suh-racc which have almost lost the power of tumbling, but are valued for pos. essing some other characteristics in an extreme degree. They arc very small, have almost globubr head., an<l a very minute beak, so that fanciers say the head of :1 perfect hinl should resemble a. cherry with a barleycorn stuck in it. Some of these weigh less than seven ounces, whereas the wild r o<;kpigcon weighs about fourteen ounces. The feet, too, arc very short and small, and the middle toe h<Ls twelve or thirteen instead of fourteen or fifteen s<;utellre. They have often only nine primary wing-feathers instead of ten <LS in all other pigeons. 1 Mr. Brent in Journal of Ilortiwlture, 1861, p. 76 ; quoted by Darwiu, Animals cmd Plants under Domestication, vol. i. p. 151. IV VARIATION U Dim DOMES'L'ICATION 93 H.ACE VIII. Jnrliw~ F1·ill-bnclc.-In these birds the hc:t k is very Rhort, a1ul the fc<.tthers of the whole body are rever cd or turn backw<.trds. HACJi~ IX. Jacobin.-Tho. c curious birds have a hood of f :tth 'rs almost enclo inO' the head :wd meeting in front of the neck The wing and tail arc tum. ually long. RA E X. Tnlmpeter. - i. tinrruished hy a tuft of feathers curling forwards over the hcn.k, and the feet very mnch feathered. They obtain their nn.mc from the peculiar voi<;c unlike that of any other pio·con. The coo is rapidly repeated, and i. continued for several mi.nntcs. The feet arc covered with feathers . o largo as often to appear like little wings. H.Af'E XI. comprise Laugher , F1·ill-backs, N1tns, Spots, and Swallows.-Thoy are all very like the common rock-pigeon, but have each some slight peculiarity. The Laughcrs ha.ve a peculiar voice, upposed to resemble a laugh. The Nuns arc white, with the head, tail, and primary wing-feath 'r: black or red. The Spot1:> <tre white, with th tail and a spot on the forehead red. The Swallow arc Rlcnc1cr, white in colour, with the head n.nd wings of some darker colour. Besides these races and sub-races a number of other kinds have been de. cribcd, and about one hundred and fifty varieties can be distingui hod. It is interesting to note that almost every part of the bird, whose variations crm ho noted and sclcctccl, has led to variations of a considerable extent, and many of these have nccessita.ted changes in the plumage and in the skeleton quite as grc:tt as any that occur in the numerous distinct species of brgc genera. The form of the slmll a.nd hcak varies enormously, so that the slml1s of the Short-faced tumbler a.nd some of the Carrier differ more than any wild pigeon., even tho. c classed in distinct genom. The breadth and number of the ribs vary, as well a.s the processes on thorn ; the nnm her of the vcrtehrm a.nd the length of the sternum also vary ; and the pcrforaLions in the sternum vary in size and sha.pe. The oil gland varies in development, and is sometimes absent. The number of the wing-feathers v<.trics, and those of the tail to an enormous extent. The proportions of the leg and feet and the number |