THE THYROID APPARATUS 77 



of congenital myxoedema, while goitre is almost invariable in 

 the antecedents of endemic cretinism. 



Hypothyrosis in children also includes the condition known 

 as infantilism. 



Infantilism, as defined by Lasegue, is a disturbance of 

 development, the salient feature of which is the persistence, in 

 both the mental and physical state, of infantile characteristics. 

 The chief clinical signs of this condition are the small size of 

 the bones and internal organs, the defective development of the 

 sexual glands and accessory sexual organs, and the childishness 

 of the mental state. 



The term infantilism was afterwards made to include those 

 cases of arrested development which result from nutritional de- 

 rangements and from diseases of the vessels, the brain, &c. This 

 form is known as infantilismus dystrophicus or typus Lorrain, 

 and its etiology is to be sought in a number of widely different 

 originating causes. It may appear, as the result of hypoplasia 

 of the vascular system (Virchow), in hereditary syphilis ; after 

 alcoholism and other forms of chronic poisoning in the parents; 

 in primary cerebral disease ; as the result of infective diseases 

 contracted in early life (tuberculosis, pellagra) ; metabolic derange- 

 ments (chlorosis) ; cardiac disease (pulmonary and mitral insuffi- 

 ciency) ; and finally, as the result of unhygienic surroundings 

 and insufficient nourishment in early childhood. 



A closer study of infantile myxoedema and cretinism, and 

 the recognition of the pathogenetic significance of the thyroid 

 gland in these conditions, led Brissaud, and after him a number 

 of French scientists (Meige, Thibierge, Hertoghe, &c.), to in- 

 vestigate the close relationship which exists between the abortive 

 forms of myxoedema and certain forms of infantilism. Brissaud 

 named these conditions infantilismus myxaedematosus, or tnyx- 

 infantilismus, and he believed that both the dystrophic and the 

 myxcedematous types were thyrogenetic in origin. 



Many authors, especially Hertoghe, ascribe all forms of 

 infantilism to disturbance of the function of the thyroid. But 

 there are others (De Sanctis, Ferranini, Anton) who lay stress 

 upon the fact that, in many cases of infantilism both slight and 

 severe, the thyroid is comparatively normal. Brissaud's type is, 

 however, well known, and its pathogenetic relation to the thyroid 

 is very generally conceded. 



Since the discovery of the interactivity of the internal secre- 

 tory organs and of the influence which certain of these organs 

 (hypophysis, suprarenals, generative glands) exercise upon 

 physical and mental development, we are accustomed to ascribe 

 those forms of infantilism which are not dystrophic in their origin 

 to an arrest of development consequent upon the abnormality of 

 one or more internal secretory organs. 



These developmental disturbances must not be confused with 



