capable of but little movement upon each other. There are two hinges, one at the elbow, and the other at the wrist; but the radius and ulna cannot move round each other, as they can in our arms, and the fingers are fixed and rigid. This would be most unfortunate if the wing had to be used as a walking or climbing limb; but it is most useful in relation to the function which the wing has to perform--that of flight. The strength of the downward stroke would be enfeebled if the bones were in a limp condition and moved upon each other. They offer, too, a firm foothold for the thick quills of the big feathers of the wing. It has been mentioned that all the evidence at our disposal points to the view that the wing has become gradually moulded into an organ of flight, from a condition in which it played a different part. The earliest bird of which we have any record had wings which were much less perfect as flying organs than those of modern birds. It seems pretty plain that the bones in that antique bird were much less rigidly fixed together, and it is equally clear that the fingers were very much more loosely attached to one another. They were also more on an equality as regards size; the great disparity evident in fig. 12 is not to be seen in the Archæopteryx. All this, of course, shows that the Archæopteryx could not have possessed the ample pinion of its more vigorous descendants of to-day. The fossil Archæopteryx looks a little like a crow would look after receiving at close quarters a charge of duck shot; but a closer examination will show that in reality all the bones are there, on one side at least. Out of the disjecta membra of the fossil numerous ‘restorations’ have been put together, which are as diverse as the minds which imagined them. We cannot really say with certainty what were the precise relations of the hand to the feathers. It seems most probable that the hand of this ‘mediæval’ bird still retained the ordinary functions of a hand; that it served its possessor to lay hold of convenient branches, from which it fluttered feebly to others. One bold speculator has insisted upon the probability that the Archæopteryx had the requisite five fingers of the presumed ancestral type; but there are no traces of them, except in so far as the lie of the feathers enables a hint to be gathered. Boring operations, or at least prospecting in the interior of the stony slab on which the fossil lies, might reveal some additional fingers; but the operation would be fraught with too obvious perils to a nearly unique object. There are a good many birds which do not, and some which cannot, fly. To the first category belong such birds as the domestic ducks and fowls, and some of the rails. These birds, when put to it--when chased by a dog, for example--can often fly; but as a rule they do not, or at most only flutter along. The Ostrich tribe and a few other birds have totally lost the power of flight. But though this is the case,