The head, however, is liable to exhibit symptoms of rachitis at a very early period of life. It is large, or appears to be so,[13] mostly for the reason that the face is proportionately small. The forehead is large, the frontal protuberances very prominent, as are also those of the parietal bones. Thus, the head is more or less square. Dilated veins are visible in and through the pale skin; there is but little hair, on the occiput less than on the rest of the head. Sometimes the occiput is quite bald, the hair having been rubbed off on the pillow. The scalp feels warm, except during perspiration. The latter is very copious, particularly on the occiput--to such an extent, indeed, that the pillow is drenched--and will remain so for months. The sebaceous follicles are often still larger and more numerous than they normally are at that age, and seborrhoea is { 147} often, though not always, met with. The sutures are wide, sometimes one or two centimeters; the posterior fontanel remains open; the large anterior fontanel is very large, being sometimes several inches long and wide. The pulse is felt very distinctly through it. The systolic cerebral murmur, which was first found by Fisher of Boston in 1833, and considered to be a positive symptom of rachitis (which certainly it is not, as it is found in almost every healthy baby with a patent fontanel), is very audible. The fontanel and sutures remain open for a long period. Instead of closing, as they do normally at the fourteenth or fifteenth month, the former ossifies about the end of the second or third year, or later. Gerhardt reports a case in which it persisted to the ninth year. The cranial bones appear to be thin, and give way under the pressure of the finger. Ordinarily, it is true, the cranial bones of every baby, even if perfectly healthy, are movable under pressure, but they are so only along the sutures, where they may retain this mobility, in some instances, a long time. Indeed, it appears that sometimes about the middle of the first year the occipital bone becomes thinned out in apparently quite healthy children. Moreover, even in the skulls of infants who were taken to be in good health small defects in the bones were found (Friedleben), with no uncomfortable symptoms at all. Therefore it is rather difficult to draw the exact boundary-line between the healthy and the morbid condition; thus it is possible that some of those cases which exhibited apparently morbid local changes without morbid symptoms may not have been diseased after all. In those, however, in which rachitis is really developed in the cranium a peculiar condition is found. In the posterior half or third of the parietal bones, either the right or the left side being more marked, there are in the tissue of the bone distinct spots in which the osseous material is not only thinned out, but has entirely disappeared. In fact, the bone is perforated, the edges of the holes being rather steep, sometimes slightly thickened, and the scalp separated from the brain only by a thin, transparent membrane, the remnant of the periosteum. These holes can be easily found through the integument. The finger, though ever so gently pressing down upon it, moves the cranium, if any be left, before it; the bone feels like paper, and the sensation as if it could be easily broken through is quite distinct and embarrassing. Such perforations are usually quite numerous; from five to twenty or more can often be counted. They are surrounded by normally hard bone, and thereby can be recognized from the flexible part of the cranium extending along the sagittal and lambdoid sutures. Where these results of rachitical softening, craniotabes, are most prominent--that is, on the part on which the infant is mostly reclining--the bone is flattened, and may remain so for life, though in the majority of cases the asymmetry will disappear. The flattening and perforations result from the same causes--viz. softening of the bones and pressure upon the bone between the pillow outside and the brain inside. With it go, hand in hand, thick rachitical deposits under the hyperæmic periosteum of other portions of the skull. Where craniotabes is largely developed on the occipital portion, the frontal and the parietal bones (in their anterior halves) are usually thus thickened. A cross-section with a knife will reveal a diameter of the new osteoid material between the periosteum and bone of one-half to one centimeter in thickness. It is very hyperæmic--even more so than the bone itself, { 148} which, when cut into, exhibits an unusual amount of blood.