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detail, as they afford coincidences with the bones in the corresponding parts of Lizards, from which important conclusions may be derived.

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As an insulated fact, it may seem to be of little moment, whether a living Lizard or a fossil Pterodactyle, might have four or five joints in its fourth finger, or its fourth toe; but those who have patience to examine the manutiæ of this structure, will find in it an exemplification of the general principle, that things apparently minute and trifling in themselves, may acquire importance, when viewed in connexion with others, which, taken singly, appear equally insignifiMinutiae of this kind, viewed in their conjoint relations to the parts and proportions of other animals, may illustrate points of high importance in physiology, and thereby become connected with the still higher considerations of natural theology. If we examine the fore-foot of the existing Lizards, (Pl. 22, B.) we find the number of joints regularly increased by the addition of one, as we proceed from the first finger, or thumb, which has two joints, to the third, in which there are four; this is precisely the numerical arrangement which takes place in the first three fingers of the hand of the Pterodactyle; (Pl. 22, c. D. E. N. o. Figs. 3038. Thus far the first three fingers of the fossil reptile agree in structure with those of the fore-foot of living Lizards; but as the hand of the Pterodactyle was to be converted into an organ of flight, the joints of the fourth, or fifth finger were lengthened, to become expansors of a membranous wing.*

* Thus in the P. Longirostris (Pl. 21, 39–42.) and P. Brevirostris, (Pl. 22, Fig. O, 39-42,) the fourth finger is stated by Cuvier to have four. elongated joints, and the fifth or ungual joint to be omitted, as its presence is unnecessary. In the P. Crassirostris, according to Goldfuss (Pl. 22, Figs. ▲, N,) this claw is present upon the fourth finger, (43) which thus has five bones, and the fifth finger is elongated to carry the wing. Throughout all these arrangements in the fore-foot, the normal numbers of the type of Lizards are maintained.

If, as appears from the specimen engraved by Goldfuss, of P. Crassi

As the bones in the wing of the Pterodactyle thus agree in number and proportion with those in the fore-foot of the Lizard, so do they differ entirely from the arrangement of the bones which form the expansors of the wing of the Bat.*

The total number of toes in the Pterodactyles is usually four; the exterior, or little toe, being deficient; if we compare the number and proportion of the joints in these four toes with those of Lizards, (Pl. 22, F, G, H, I,) we find the agreement as to number, to be not less perfect than it is in the fingers; we have, in each case, two joints in the first, or great toe, three in the second, four in the third, and five in the fourth. As to proportion also, the penultimate joint is always the longest, and the antepenultimate, or last but two, the shortest; these relative proportions are also precisely the same, as in the feet of Lizards.† The apparent

rostris, (Pl. 22, N, 44, 45,) the fifth finger was elongated to expand the wing, we should infer from the normal number of joints in the fifth finger of Lizards being only three, that this wing finger had but three joints. In the fossil itself the first two joints only are preserved, so that his conjectural addition of a fourth joint to the fifth finger, in the restored figure, (Pl. 22, A, 47) seems inconsistent with the analogies, that pervade the structure of this, and of every other species of Pterodactyle, as described by Cuvier.

* The Bat, see Pl. 22, м, 30, 31, the first finger or thumb alone, is free, and applied to the purpose of suspension and creeping; the expansors of the wing are formed by the metacarpal bones, (26-29,) much elongated and terminated by the minute phalanges of the other four fingers, 32-45, thus presenting an adaptation of the hand of the mammalia to the purposes of flight, analogous to that which in the fossil world, the Pterodactyle affords with respect to the hand of Lizards.

According to Goldfuss the P. Crassirostris had one more toe than Cuvier assigns to the other species of Pterodactyles; in this respect it is so far from violating the analogies we are considering, that it adds another approxi mation to the character of the living Lizards; we have seen that it also differs from the other Pterodactyles, in having the fifth, instead of the fourth finger elongated, to become the expansor of the wing.

It is however probable that the fifth toe had only three joints, for the

use of this disposition of the shortest joints in the middle of the toes of Lizards, is to give greater power of flexion for bending round, and laying fast hold on twigs and branches of trees of various dimensions, or on inequalities of the surface of the ground or rocks, in the act of climbing, or running.*

All these coincidences of number and proportion, can only have originated in a premeditated adaptation of each part to its peculiar office; they teach us to arrange an extinct animal under an existing family of reptiles; and when we find so many other peculiarities of this tribe in almost every bone of the skeleton of the Pterodactyle, with such modifications, and such only as were necessary to fit it for the purposes of flight, we perceive unity of design pervading every part, and adapting to motion in the air, organs which in other genera are calculated for progression on the ground, or in the water.

If we compare the foot of the Pterodactyle with that of the Bat, (see Pl. 22, к,) we shall find that the Bat, like most other mammalia, has three joints in every toe, excepting the first, which has only two; still these two, in the Bat, are equal in length to the three bones of the other toes, so that the five claws of its foot range in one strait line, forming altogether the compound hook, by which the animal suspends itself in caves, with its head downwards, during its long periods of hybernation; the weight of its body being, by this contrivance, equally divided between each of the ten toes. The unequal length of the toes of the Pterodactyle must have rendered it almost impossible for its claws to range uniformly in line, like those of the Bat, and as no single claw could have supported for a long time the weight

same reasons that are assigned respecting the number of joints in the fifth finger. In the P. Longirostris, Cuvier considers the small bone, (Pl. 21, 5, 6,) to be a rudimentary form of the fifth toe.

* A similar numerical disposition prevails also in the toes of birds, at. tended by similar advantages.

of the whole body, we may infer that the Pterodactyles did not suspend themselves after the manner of the Bats. The size and form of the foot, and also of the leg and thigh, show that they had the power of standing firmly on the ground, where, with their wings folded, they possibly moved after the manner of birds; they could also perch on tress, and climb on rocks and cliffs, with their hind and fore-feet conjointly like bats and Lizards.

With regard to their food, it has been conjectured by Cuvier, that they fed on insects, and from the magnitude of their eyes that they may also have been noctivagous. The presence of large fossil Libellulæ, or Dragon-flies, and many other insects, in the same lithographic quarries with the Pterodactyles at Solenhofen, and of the wings of coleopterous insects, mixed with bones of Pterodactyles, in the oolitic slate of Stonesfield, near Oxford, proves that large insects existed at the same time with them, and may have contributed to their supply of food. We know that many of the smaller Lizards of existing species are insectivorous: some are also carnivorous, and others omnivorous, but the head and teeth of two species of Pterodactyle, are so much larger and stronger than is necessary for the capture of insects, that the larger species of them may possibly have fed on fishes, darting upon them from the air after the manner of Sea Swallows and Solan Geese. The enormous size and strength of the head and teeth of the P. Crassirostris, would not only have enabled it to catch fish, but also to kill and devour the few small marsupial mammalia which then existed upon the land.

The entire range of ancient anatomy, affords few more striking examples of the uniformity of the laws, which connect the extinct animals of the fossil creation with existing organized beings, than those we have been examining in the case of the Pterodactyle. We find the details of parts which, from their minuteness should seem insignificant, acquiring great importance in such an investigation as we

are now conducting; they show not less distinctly, than the colossal limbs of the most gigantic quadrupeds, a numerical coincidence, and a concurrence of proportions, which it seems impossible to refer to the effect of accident; and which point out unity of purpose, and deliberate design, in some intelligent First Cause, from which they were all derived. We have seen that whilst all the laws of existing organization in the order of Lizards, are rigidly maintained in the Pterodactyles; still, as Lizards modified to move like birds and Bats in the air, they received, in each part of their frame, a perfect adaptation to their state. We have dwelt more at length on the minutiae of their mechanism, because they convey us back into ages so exceedingly remote, and show that even in those distant eras, the same care of a common Creator, which we witness in the mechanism of our own bodies, and those of the myriads of inferior creatures that move around us, was extended to the structure of creatures, that at first sight seem made up only of monstrosities.

SECTION IX.

MEGALOSAURUS.*

THE Megalosaurus, as its name implies, was a Lizard, of great size, of which, although no skeleton has yet been found entire, so many perfect bones and teeth have been discovered

* This genus was established by the Author, in a Memoir, published in the Geol. Trans. of London, (Vol. I., N. S. Pt. 2, 1824,) and was founded upon specimens discovered in the oolitic slate of Stonesfield, near Oxford, the place in which these bones have as yet chiefly occurred. Mr. Mantell has discovered remains of the same animal in the Wealden fresh-water for. mation of Tilgate Forest; and from this circumstance we infer that it existed during the deposition of the entire series of oolitic strata. The author, in

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