In a pronounced case of rickets the effect of the bone lesions is very .striking and peculiar : The skull is large with a long antero-posterior diameter, and often, on account of the comparatively small size of the face, looks larger than it really is. The forehead is square from exaggeration of the bosses of the frontal bones, and is sometimes very prominent from the development in the bone of cellular cavities. The fontanelle is large and remains open long after the end of the second year. Sometimes, if the size of the brain is increased, or there is excess of fluid in the skull cavity, the sutures in connection with the fontanelle can be felt to be more or less distinctly gaping. On account of the thickening of the edges of the flat bones the margins of the sutures and fontanelle are elevated, so that the latter feel depressed and the sutures are indicated by furrows. The posterior fon tanelle has usually disappeared before the beginning of the illness, but in extreme cases, where the disease began early and the symptoms are pro nounced, it may be felt to be still unclosed.
In every case of rickets the condition known as " cranio-tabes " and described by Elasser should be searched for. It is best detected by with the tips of the fingers on the posterior surface of the head. cranio-tabes be present, spots will be felt where the bone is thin, soft, and elastic, as if at this point it had been converted into tightly stretched parchment. The spots are seldom larger than the diameter of a good-sized pea, and are usually confined to the occipital bone. They are caused by absorption of the imperfectly ossified bone from its compression between the pillow and the brain as the child lies in his cot. They may be met with as soon as the third month of life, and are said to be the ear liest sign of the disease.
A rickety child's hair is usually thin, and is often kept moist by the copious perspirations to which the head is subject whenever the patient falls asleep. In most rickety children a systolic murmur of variable inten sity can beeheard with the stethoscope applied over the fontanelle. Ac cording to Senator, the symptom merely shows that an ossified membrane is better fitted than the cranial bones to transmit to the ear sounds gener ated in the cerebral vessels. There is no doubt that it is rarely heard in children in whom the fontanelle has closed. The murmur is sometimes curiously loud. Not long ago a pallid, flabby little girl, between two and three years old, the subject of rickets, was brought to me from the coun try on account of a strange noise which was heard at times to proceed from her head. The child had cut all her teeth, but was very weak on her legs. She was subject to attacks of stridulous laryngitis. The fontanelle was not quite closed. Her heart and lungs were healthy. It was said that in this child a noise like " the purring of a kitten," not continuous, but distinctly intermittent, "like a pulsation," could be beard at times. It was loudest at the right side of the head. It was not especially loud after exertion, and was only occasionally audible. It was heard best immedi ately the child awoke in the morning, and was then distinctly perceptible several yards from her cot. During the child's visit to me no cerebral or other murmur could be heard with the stethoscope. Still, I had no reason to doubt the good faith of the relatives. The mother, who gave me the account, told her tale in a straightforward manner, with the air of one who was eager to receive an explanation of a mystery which had puzzled her and made her anxious.
The chief cause of the smallness of the face is the imperfect develop ment of the jaws. Fleischmann has drawn attention to the angularity, and flatness anteriorly, of the lower jaw. It has lost its normal curve. The in'. cisors are quite in a straight line ; then at the situation of the eye-teeth the jaw forms a sharp angle and bends abruptly backwards. This is due to imperfect growth of the middle portion of the jaw. Baginsky describes in addition an occasional want of symmetry between the two halves of the bone, which gives the appearance of one side being higher than the other. The effect of this delayed development of the jaw upon dentition is very important. Rickety children are late in teething. At whatever age be fore the completion of dentition the disease may begin, directly the cranial or facial bones become affected there is complete arrest in dental develop ment. Thus, if the disease occurs before any teeth have been cut, their appearance may be indefinitely delayed. If several teeth have already pierced the gum the process stops there, and mouths may elapse before others are seen. When, however, the teeth do come they are usually cut without much trouble ; but they are in most cases of bad quality from perfect development of the dental enamel, and quickly blacken and decay.
The chest is deformed in a very characteristic manner on account of the inability of the softened ribs to resist the pressure of the atmosphere. Under normal conditions, when the ribs rise and the chest expands in the act of inspiration, the solid framework of the thorax is able to withstand the pressure of the expired air, and the chest easily enlarges to allow of inflation of the lungs. Air rushes through the wind-pipe to dilate the pulmonary tissue in proportion as the chest-walls expand. In the rickety chest, on the contrary, the ribs are not firm but yielding. Consequently the framework of the thorax is not rigid enough to resist the pres sure of the air from without, and when the effort is made to expand the chest the softened ribs are forced in at the sides—the parts where they are least supported. This sinking in of the ribs throws the sternum for wards. We therefore find the chest grooved laterally and the breast-bone prominent and sharp. The groove is broad and shallow, and reaches from the second or third rib to the hypochondrium. The bottom of the depres sion is formed by the ribs outside their junction with the cartilages. Therefore along the inner side of the groove the swollen ends of the ribs can be seen, looking like a row of large beads under the skin. The groove is deepest in children who have suffered much from pulmonary catarrh. In such subjects the impediment to the entrance of air, already existing, is increased by the narrowing in the calibre of the smaller tubes induced by the derangement ; and the softened ribs receive still less support from the lung tissue beneath them. In a chest so deformed each inspiration increases the depth of the lateral groove, and at the same time produces a deep furrow which passes horizontally across the chest at the level of the epigastrium. This furrowing of the surface has been shown by Sir Wil liam Jenner to be due not to the traction of the diaphragm, as was taught by Rokitansky, but like the lateral grooves of the chest to atmospheric pressure. The liver, stomach, and spleen support the parietes under which they lie, and prevent the wall at these points from falling in.