Bircher (Trans. Congress Amer. Phys. and Surgs., vol. iv, p. 203, '97) stands alone with his theory of the non-de pendence of cretinism on the thyroid gland, but the accumulating evidence is so strongly opposed to such an idea that his proposition demands more confirma tory evidence than he has brought for ward to substantiate it.
Such are a few of the theories which have been suggested to explain the con ditions found in cretinism, but, except for the microbic theory of Combe, they do not explain the ultimate cause of the atrophy or degeneration of the gland. Wir..mam OSLER and RUPERT NORTON%) In this disease as in all obscure ones we find numerous causes given as pos sible factors, but none of them seem to play an important part; alcohol, syphilis, and tuberculosis have been considered in this relation, but no definite connection can be traced between them and cretin ism. It has been suggested that cretin ism may follow "alcoholic conceptions." Various nervous diseases in the families of both father and mother, or in the parents themselves, have been looked to as producing the cretinoid state, but no proof can be shown to confirm this theory. Cretinism may, however, follow as a very rare result some of the infec tious fevers; for example, typhoid, scar let fever, pneumonia, and whooping cough; also an injury. Myxcedema in adults has followed erysipelas and acute rheumatism. Women who have once given birth to a cretin are likely to give birth to more if they become pregnant, but this may be prevented in some in stances by placing the mother under thy roid treatment during her pregnancy. And, again, women who have lived in healthy countries and given birth to healthy children may give birth to cre tins if they remove to a place where cre tinism is endemic: but may, again, give birth to healthy children, if they return to a healthy locality.
[It has been suggested that as cretin ism is more common in the female sex than in the male, that the thyroidal con gestions caused by menstruation, preg nancy, and lactation may play a part in bringing about degenerative altera tions of the gland. Cretinism does occur among the negroes of the United States, but is rare. "In cretins 25 per
cent. have no thyroid gland, or it is replaced by connective tissue; in the re maining 75 per cent. the function is suppressed as a result of degeneracy of the gland, and in these cases, according to Kocher, there is oftenest a colloid goitre" (Combe, Revue Mod. de la Suisse Romande, Amino xvii, Nos. 2 to 6). Goitre is more common in females than in males, and cretinism, with or without goitre, is more common in females. Griesinger has pointed out that, where cretinism is endemic, besides cretins, micretins, and the goitrous, one finds also a quantity of imbeciles, deaf-mutes, stut terers, dwarfs, and degenerates. The French Commission came to the conclu sion that goitrous parents engender cre tins in a much large proportion com paratively than non-goitrous parents. WILLIAM OSLER and RUPERT NORTON.] Sound and strong parents who have lived far from regions in which cretinism is endemic and had there begotten nor mal children, after moving into a dis trict of cretinism have begotten one or more cretins. In some of these cases the parents, either father, mother, or both, became victims of goitre, but with out a trace of cretinism. Moreover, after such parents have returned to their former place of residence, they again begot healthy children. In some cases normal children were begotten in the cretin districts by parents to whom cretins were also born.
The same influences which lead to goitre are a cause of cretinism. When ever goitre or cretinism appears in chil dren, one or the other of the parents will he found to have goitre. The discom forts caused by goitre, no matter how intense they may be, never lead directly to cretinism, not even in the slightest degree, but cretinism arises only and solely, when, by degeneration of the thyroid gland through goitre, or equally well by means of some other injury of the gland, its function is destroyed or seriously impaired. Inherited and, at the same time, congenital cretinism is derived from the mother alone; while inherited cretinism, which appears only after a lapse of months, or years, is de rived from the father alone. Inherited and congenital cretinism is an exception.