I was a student of law at a time when Sir Richard Owen was lecturing on Extinct Fossil Reptiles. The skill of the great master, who built bones together as a child builds with a box of bricks, taught me that the laws which determine the forms of animals were less understood at that time than the laws which govern the relations of men in their country. The laws of Nature promised a better return of new knowledge for reasonable study. A lecture on Flying Reptiles determined me to attempt to fathom

The history of life on the earth during the epochs of geological time unfolds no more wonderful discovery among types of animals which have become extinct than the family of fossils known as flying reptiles. Its coming into existence, its structure, and passing away from the living world are among the great mysteries of Nature. The animals are astonishing in their plan of construction. In aspect they are unlike birds and beasts which, in this age, hover over land and sea. They gather into themse

The relations of reptiles to other animals may be stated so as to make evident the characters and affinities which bind them together. Early in the nineteenth century naturalists included with the Reptilia the tribe of salamanders and frogs which are named Amphibia. The two groups have been separated from each other because the young of Amphibia pass through a tadpole stage of development. They then breathe by gills, like fishes, taking oxygen from the air which is suspended in water, before lun

Such are a few illustrations of ways in which reptiles resemble other animals, and differ from them, in the organs by means of which the classification of animals is made. But such an idea is incomplete without noticing that the bony framework of the body associated with such vital organs also shows in its chief parts that reptiles are easily recognised by their bones. I will therefore briefly state how reptiles are defined in some regions of the skeleton, for in tracing the history of reptile l

The nature of a reptile is now sufficiently intelligible for something to be said concerning flight, and structures by means of which some animals lift themselves in the air. It is not without interest to remember that, from the earliest periods in human records, representations have been made of animals which were furnished with wings, yet walked upon four feet, and in their typical aspect have the head shaped like that of a bird. They are commonly named Dragons. The effigy of the dragon surviv

Late in the eighteenth century, in 1784, a small fossil animal with wings began to be known through the writings of Collini, as found in the white lithographic limestone of Solenhofen in Bavaria, and was regarded by him as a former inhabitant of the sea. The foremost naturalist of the time, the citizen Cuvier—for it was in the days of the French Republic—in 1801, in lucid language, interpreted the animal as a genus of Saurians. That word, so familiar at the present day, was used in the first hal

There is only one safe path which the naturalist may follow who would tell the story of the meaning and nature of an extinct type of animal life, and that is to compare it as fully as possible in its several bones, and as a whole, with other animals, especially with those which survive. It is easy to fix the place in nature of living animals and determine their mutual relations to each other, because all the organs—vital as well as locomotive—are available for comparison. On such evidence they a

We shall endeavour to ascertain what marks of its grade of organisation the Pterodactyle has to show. The organs which are capable of modifying the bones are probably limited to the kidneys, the brain, and the organs of respiration. It may be sufficient to examine the latter two. Hermann von Meyer, the historian of the Ornithosaurs of the Lithographic Slate, as early as 1837 described some Pterodactyle bones from the Lias of Franconia, which showed that air was admitted into the interior of the

While these animals are incontestably nearer to birds than to any other animals in their plan of organisation, thus far no proof has been found that they are birds, or can be included in the same division of vertebrate life with feathered animals. It is one of the oldest and soundest teachings of Linnæus that a bird is known by its feathers; and the record is a blank as to any covering to the skin in Pterodactyles. There is the strongest probability against feathers having existed such as are kn

The backbone is a more deep-seated part of the skeleton than the head. It is more protected by its position, and has less varied functions to perform. Therefore it varies less in distinctive character within the limits of each of the classes of vertebrate animals than either the head or limbs. It is divided into neck bones, the cervical vertebræ; back bones, the dorsal vertebræ; loin bones, the lumbar vertebræ; the sacrum, or sacral vertebræ, which support the hind limbs; and the tail. Of these

The bones of the hip-girdle form a basin which incloses and protects the abdominal vital organs. It consists on each side of a composite bone, the unnamed bones— ossa innominata of the older anatomists—which are each attached to the sacrum on their inner side, and on the outer side give attachment to the hind limbs. As a rule three bones enter into the borders of this cup, termed the acetabulum, in which the head of the thigh bone, named the Femur, moves with a more or less rotary motion. There

The sternum is always a distinguishing part of the bony structure of the breast. In Crocodiles it is a cartilage to which the sternal ribs unite; and upon its front portion a flat knife-like bone called the interclavicle is placed. In lizards like the Chameleon, it is a lozenge-shaped structure of thin bony texture, also bearing a long interclavicle, which supports the clavicular bones, named collar bones in man, which extend outward to the shoulder blades. Among mammals the sternum is usually n

Such are the more remarkable characters of the bones in a type of animal life which was more anomalous than any other which peopled the earth in the Secondary Epoch of geological time. Its skeleton in different parts resembles Reptiles, Birds, and Mammals; with modifications and combinations so singular that they might have been deemed impossible if Nature's power of varying the skeleton could be limited. Since Ornithosaurs were provided with wings, we may believe the animals to some extent to h

Cuvier's discourse on the revolutions of the Earth made the Pterodactyle known to English readers early in the nineteenth century. Dr. Buckland, the distinguished professor of Geology at Oxford, discovered in 1829 a far larger specimen in the Lias of Lyme Regis, and it became known by a figure published by the Geological Society, and by the description in his famous Bridgewater Treatise, p. 164. This animal was tantalising in imperfect preservation. The bones were scattered in the clay, so as to

The Stonesfield Slate in England, which corresponds in age with the lower part of the Great or Bath Oolite, yields many evidences of terrestrial life—land plants, insects, and mammals—preserved in a marine deposit. A number of isolated bones have been found of Pterodactyles, some of them indicating animals of considerable size and strength. The nature of the limestone was unfavourable to the preservation of soft wing membranes, or even to the bones remaining in natural association. Very little i

When staying at Swanage, in Dorsetshire, many years ago, I had the rare good fortune to obtain from the Purbeck Beds the jaw of a Pterodactyle, which had much in common in plan with the Cycnorhamphus Fraasii from the Lithographic Slate, which is preserved at Stuttgart. The tooth-bearing part of this lower jaw is 8 inches long as preserved, extending back 3 inches beyond the symphysis portion in which the two sides are blended together. It is different from Professor Fraas's specimen in having th

When an attempt is made to determine the place in nature of an extinct group of animals and the relation to each other of the different types included within its limits, so as to express those facts in a classification, attention is directed in the first place to characters which are constant, and persist through the whole of its constituent genera. We endeavour to find the structural parts of the skeleton which are not affected by variation in the dentition, or the proportions of the extremitie

Enough has been said of the general structure of Pterodactyles and the chief forms which they assumed while the Secondary rocks were accumulating, to convey a clear idea of their relations to the types of vertebrate animals which still survive on the earth. We may be unable to explain the reasons for their existence, and for their departure from the plan of organisation of Reptiles and Birds. But the evidence has not been exhausted which may elucidate their existence. Sometimes, in problems of t

Ornithosauria have many characters inseparably blended together which are otherwise distinctive of Reptiles, Birds, and Mammals, and associated with peculiar structures which are absent from all other animals. They are not quite alone in this incongruous combination of different types of animals in the same skeleton. Dinosaurs, which were contemporary with Ornithosaurs, approximate to them in blending characters of Birds with the structure of a Reptile and something of a Mammal in one animal. If

The best public collections of Ornithosaurian remains in England are in the British Museum (Natural History); Museum of Practical Geology, Royal College of Surgeons; the University Museum, Oxford; Geological Museum, Cambridge; and the Museum of the Philosophical Society at York. Detailed descriptions and original figures of the principal specimens mentioned or referred to may be found in the following writings:— H. v. Meyer, Reptilien aus dem Lithograph . Schiefer . 1859. Folio. v. Quenstedt, Pt