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I have much pleasure in expressing my thanks to the numerous friends, who have so materially assisted me, in obtaining the specimens necessary to the pursuit of this subject. I shall always be happy to show the preparations which form the groundwork of this paper to any members of the profession, to whom I again take the opportunity of stating, I shall feel much indebted for every opportunity they can afford me of dissecting the organ of hearing, especially when it is diseased.
12, Argyll Place, St. James's,
UPON THE GROWTH OF THE SKULL.
BY ALEXANDER SHAW, Esq.,
SURGEON TO THE MIDDLESEX HOSPITAL.
READ JUNE 27TH, 1843.
Some years ago the Society did me the honour to publish in their Transactions, a paper on certain peculiarities in the conformation of the skeleton produced by rickets.* In that paper, my principal object was to show that, independently of the softening and consequent incurvation of the bones to which rickets has been long known to give rise, it has the effect of arresting the growth; and, as between infancy and adolescence, a remarkable change takes place in the relative proportions of the figure,
* Vol. xvii. The same subject was further pursued in two papers communicated by the author to the London Medical Gazette, March 1835, and Nov. 1835.
so that those of the adult differ widely from those of the child, the progress of that change is interrupted by the stoppage ; and the result is, that persons so affected, when they arrive at adolescence, have the configuration characteristic of the child, more or less distinctly marked, instead of that proper to the adult.
Since presenting these views to the Society, my attention has been directed in a more particular manner than before, to the form of the head in individuals distorted from the same disease ; and I have observed that there is in this part a want of the correct relative proportions between the two principal divisions of which it consists—the cranium, and the face-analogous to what is found in the body generally. As in prosecuting that inquiry, several questions, interesting both in a physiological and practical view, have presented themselves to my notice, I beg to lay my observations before the Society.
It being necessary for the illustration of my present subject, to point out more fully the effects produced upon the relative dimensions of the figure generally by rickets, I will briefly recapitulate some of the facts contained in my former paper.
The short stature of persons who have suffered during childhood from that disease has often been observed. But it may not have been so commonly remarked that, (making allowance for the loss of height caused by the greater or less incurvations of the bones in such individuals,) certain parts of the
figure are always stunted to a greater degree than others. The head, trunk, and upper extremities continue about their natural size ; while the pelvis and lower extremities are peculiarly diminutive.
This peculiarity may be seen by looking at the shape of those persons deformed from rickets, who are met with in such numbers in the streets of this metropolis. But to verify my observation more accurately, I took the measurements of the bones in the upper and lower divisions of the body in several adult skeletons deformed from the disease; and compared them with corresponding measurements of the natural skeleton. The result was, that whereas the defect of growth in the superior division was equal only to Igth of the whole, it was as much as įrd in the inferior division.
The cause of this difference may be thus explained. In the process of growth, all parts of the frame do not increase at the same rate. If such were the law of development, the proportions would be the same at adolescence as in childhood. But that is not the case. In the child, the upper part, including the head, trunk, and upper extremities, is of large bulk compared with the pelvis and lower extremities. But in the adult, the head, trunk, and upper extremities are particularly light and small, and the pelvis and lower extremities are broad and powerful. And important objects are attained by this difference in the conformation. The proportions in infancy have reference to parturition; the head is of large size compared with the rest of the body,
in order that, while the fætus is floating in the liquor amnii, the head may gravitate to the os uteri, and by closing that orifice prevent the presentation of the hands or feet; and, secondly, that when delivery commences, and the head is expelled first, it may dilate the parts, and allow the hips to pass rapidly, so as to prevent the umbilical cord being compressed and the circulation through the placenta stopped before the child can respire. But the configuration so admirably adapted for the safe delivery of the child is incompatible with man carrying his body erect. To possess that power, which belongs exclusively to him, it is necessary that the pelvis should be expanded, to afford a secure basis for the trunk, and the lower extremities elongated and strong, to give freedom and power of motion to the limbs. Such a change, however, in the relative proportions of the figure cannot be effected except by the growth of the pelvis and of the lower extremities proceeding with greater activity than that of the head, chest, and upper extremities. And this, observation shows, is the actual course by which the several divisions attain their mature form. Hence it follows, that if, by the prevalence of a diseased action capable of retarding the growth, the natural process is interrupted, there will not only be a deficiency of size in all the body, but the change in the relative proportions of the figure which occurs simultaneously will be interfered with; and the patient, when arrived at maturity, will retain, in a greater or less degree, according to the severity or long conti