"At the lower spine are two more ribs extended horizontally when open, jointed again to the hips, and long enough to meet the joint on the contrary side cross the belly: and from the hip-joint, which is on the outermost edge of the hip-bone, runs a pliable cartilage quite down the outside of the thigh and leg to the ancle; from which there branch out divers other ribs, horizontally also when open, but, when closed, they encompass the whole thigh and leg, rolling inwards cross the back of the leg and thigh, till they reach and just cover the cartilage. The interstices of these are filled up with the same membrane. From the two ribs which join to the lower spine-bone, there hangs down a sort of short apron, very full of plaits, from hip-joint to hip-joint, and reaches below the buttocks, half way or more to the hams. This has also several small limber ribs in it. Just upon the lower spine-joint, and above the apron, as I call it, there are two other long branches, which, when close, extend upon the back from the point they join at below to the shoulders, where each rib has a clasper, which, reaching over the shoulders, just under the fold of the uppermost branch {160} or ribs, hold up the two ribs flat to the back, like a V, the interstices of which are filled up with the aforesaid membrane. This last piece, in flight, falls down almost to the ancles, where the two claspers, lapping under each leg within-side, hold it very fast; and then, also, the short apron is drawn up, by the strength of the ribs in it, between the thighs forward, and covers as far as the rim of the belly. The whole arms are covered also from the shoulders to the wrist with the same delicate membrane, fastened to ribs of proportionable dimensions, and jointed to a cartilage on the outside in the same manner as on the legs. It is very surprising to feel the difference of these ribs when open and when closed; for closed, they are as pliable as the finest whale-bone, or more so; but, when extended, are as strong and stiff as a bone. They are tapering from the roots, and are broader or narrower, as best suits the places they occupy, and the stress they are put to, up to their points, which are almost as small as a hair. The membrane between them is the most elastic thing I ever met with, occupying no more space, when the ribs are closed, than just from rib to rib, as flat and smooth as possible; but, when extended in some postures, will dilate itself surprisingly,