Virchow's researches have clone much to elucidate the chief feature of cretinism. According to this authority, it consists in an abnormal tendency to ossification and coalescence of the three bones which represent the bodies of the last three cranial vertebrie, viz., the basilar process of the oc cipital bone, the post-sphenoidal, and the pm-sphenoidal bones. In the normal condition ossification in these bones goes on slowly from behind forwards, and traces of unossified cartilage may be found as late as the thirteenth year. During the whole of this time the cartilaginous parts are still growing, and allow of expansion of the base of the skull and en largement of the cranial cavity in proportion to the wants of the growing brain. In the cretin, in whom ossification in these parts takes place early, the base of the skull cannot elongate ; the distance from the crista galli to the occipital foramen remains short ; the corresponding parts of the brain are imperfectly developed, and the form of the skull is modified. Moreover, the bones of the skull are in many cases greatly thickened and the fora mina narrowed. The bones of the limbs frequently show the same ten dency to rapid ossification, and the shafts form early union with their epiphyses. Consequently, the growth of the bones is imperfect. The brain undergoes many modifications. Important parts, such as the gan glia at the base, are often ill developed, the medulla oblongata may be small, and the fissure of Sylvius shallow and ill defined.
The physical and mental characteristics of the cretin are well illustrated by a case which was under my care in the East London Children's Hospi tal. The patient was a little girl, aged seven years, who bad come of a healthy family on both sides. She had five perfectly healthy brothers and sisters. The family lived in Shadwell, in the neighbourhood of the hospi tal. The child was said to have been a fine baby at birth, but as the months passed no teeth appeared, and she showed no inclination to stand or even crawl upon the floor. She generally seemed very dull and apa thetic, but sometimes brightened up and became more lively.
At seven years of age, when admitted into the hospital, she was barely thirty-one inches in height. She looked very broad for her height, and weighed thirty-one pounds eight ounces. Head large, nineteen inches in circumference, covered by long, sparse, coarse hair of a dull reddish-brown colour ; features large and coarse ; bridge of nose depressed ; eyes wide apart ; lips thick and pouting ; mouth generally kept half open ; teeth square, as if worn down ; tongue large ; eyes gray and dull-looking ; expres sion vacant as a rule, but sometimes brightening up when amused with a doll or ball. No trace of a thyroid gland could be discovered ; above each clavicle was a semi-globular mass, about the size of a Tangerine orange. The skin was rather dry and shrivelled-looking, with a yellowish
tint. The chest was well formed. There was no beading of the ribs or other sign of rickets. The tibiae were somewhat bowed outwards, but the limbs were massive and the flesh firm.
The child smiled when spoken to, and could say the word "doll," but appeared to apply it indifferently to all kinds of toys. She could not walk, but crawled about on her hands and feet, keeping her knees raised. When she reached a table or bed, she would raise herself into an upright position with her hands and stand holding by it. The child passed urine and faeces in the bed. Her temperature was habitually subnormal.
The soft globular lumps above the clavicles are frequent in the sporadic form of cretinism. In Mr. Curling's cases they were found after death to consist of fatty tissue.
In another case which came under my notice the patient, who had the appearance of a child, was really over seventeen years of age. His height was half an inch under three feet, his weight, thirty-six pounds fourteen ounces. He had all the physical peculiarities described in the previous case, but was more intelligent and cleanly in his habits. He could answer simple questions as to his food intelligibly. He had the same fatty masses in the supraclavicular hollows, and no thyroid body could be felt. His genitals were those of a child, and he never manifested any sexual propensities.
The symptoms of cretinism seldom appear before the sixth or seventh month. The head is usually large, for cretins never belong to the micro cephalic type. The palate is often flat, and not highly arched, as in ordinary congenital idiocy. These patients are usually quiet and good-tempered, although subject to occasional fits of passion. Their senses are often dull, and they endure great cold and heat without apparent discomfort. It is, however, one of the characteristics of idiots generally that their senses are obtuse : they can often bear pain with singular indifference; their taste is not uncommonly impaired or perverted, and sometimes they have but a faint sense of smell. Often their sight is defective from congenital cata ract, or imperfect sensibility of the retina, or hypermetropia with diminished accommodation ; but unless they have suffered from disease of the ear, their hearing is usually of normal acuteness.
The mental condition of idiots has many varieties. In the lowest form there is complete apathy and torpor ; no power of attending to or even recognising their own wants, and no capacity to speak or to understand words spoken to them. Such beings can only make unintelligible noises. They have not the slightest power of will, and seem to have little power of originating a movement, but often repeat mechanically some automatic motion of the head, the body, or a limb.