It is necessary, in order to explain this, that we anticipate in one or two points, the enumeration of the organs. G. observes, that a very prominent swelling of the forehead is characteristic of young children, and that as they advance in years this protuberance diminishes, and the forehead retreats. There is another observation which every one has made, that the faculty and the habit of attention is peculiar to children, that they have a facility and felicity in making observations. which seem to surpass what we afterwards remark in them. Hence, says Gall, the aptness of most parents to imagine their children, in whom they remark this sagacity, are possessed of singular talents; when a few years are passed over, the wonder ceases, and the miracle of three or six years old is an ordinary boy at ten or twelve. G. connects these observations together by placing the organs of observation in this district of the os frontis, as will be afterwards more particularly pointed

out.

This is also confirmed in the organ of the sexual impulse, which is seated in the cere bellum, as will be shewn hereafter. It is known that the cerebellum is, in proportion to the cerebrum, very small in children, compared with its size in adults. The gra

dual

dual developement of this organ may be perceived by comparing skulls at different periods of life. In children, for instance, that part of the skull which corresponds with the cerebellum, between the two mamillary processes of the ossa temporum, measured across, occupies one inch and an half; and at the same time another part of the skull corresponding with other organs, measures, between the same processes and the summit of the ossa parietalia, three inches. But with encreasing years, as the sexual impulse and its organ are more and more developed, this proportion is no longer to be found on the skull; and the space between the mamillary processes approaches (as is demonstrated by a comparison of skulls of all ages) the breadth of the skull between the mamillary processes and the summit of the ossa parietalia; till at length, when the individual has arrived at his full growth, it equals and even surpasses it.

If this active power of the brain in forming the skull, which passively yields to all influence from within, while it resists all pressure from without, be established; how are we to account for the facts stated by travellers concerning the artificial modelling of the head by savages. G. objects to these

state

statements, and considers them as not being entitled to much weight, from their not having proceeded from anatomists, and not being confirmed by any skulls brought into Europe for examination. He knows, he says, that nothing short of extreme violence could produce any permanent effect upon the shape of the skull; and he appeals to observation, There are many provinces of Germany in which persons, and particularly women, are accustomed from their infancy to carry heavy burthens upon their heads, but though this has subsisted for generations, it is not found that any flatness is prevalent on the skulls of such people. But where the bone has been broken, it would follow that if death do not ensue, yet the organs immediately under the injured part would be paralysed and injured; hence it is found, that the same travellers who give an account of the deformity thus violently caused in the skull, also relate that among the same people extreme stupidity and idiotcy are very frequent,

5.) But does not ossification proceed ac cording to certain laws of crystallisation, according to which we assume that the sinus of the os frontis and the upper jaw bone arise? How then can the brain determine the form of the skull ?

To

To this it may be answered, that we find in the whole economy of nature, that the law by which the inferior organisation proceeds is, in a manner, subdued and rendered of no effect by the action of higher laws. Thus, during the existence of animal life, we find the mechanical and chymical properties of matter, as it were, suspended. In like manner, here too, the laws of crystallisation are rendered invalid by the superior energy of the living brain. Besides this, we often observe that the brain has power to restore the inward lamina of the skull on which it immediately acts, while the outward plate retains its injury. As after trepanning and wounds, and where the sutures separate in an hydrops cerebri, only the inner, not the outer plate, is restored; yet if the process of ossification were independent of the brain, we might expect a like reproduction of both. On the other hand, where the brain likewise is injured, then the inner plate is not restored, and disease always remains. The cases of hydrops cerebri strikingly shew the power of the brain; the skull swells enormously, and the membranes, which before united the bones, themselves harden to bone. These statements were confirmed by the production

of

し

of a skull on which this partial reproduction, &c. could be perceived.

6.) It has been suggested that the form and eminencies of the skull may be attributed to the action of the muscles affixed to it, as we see that the muscles elsewhere form such eminencies and protuberancies. But this ob jection is sufficiently refuted by the impossibility of the muscles acting on the inner plate of the skull, with which the outer plate runs parallel, even in advanced life, and when the lamina are at a distance, Besides this, there are parts of the skull marked by protuberancies, which are not covered with muscle; as for instance, the swelling of the upper part of the os occiputis in women (the organ of parental affection) which is much stronger in them than in men, and on which no muscle acts.

7.) But if the growth and developement of the brain and its parts have influence upon the form of the skull, in like manner the decrease or diseased imperfection of the brain should also affect it.

And this is found in fact to be the case. When in old age the powers of the mind. decay, the brain also, as it were, shrinks; the circumvolutions sink in, and interstices are formed.