164 THE SEX-COMPLEX 



incompletely these circumstances the absence of menstruation is the 



puberty. only abnormal phenomenon. 



Incompletely delayed puberty may be caused by all 

 the conditions just described as responsible for completely 

 delayed puberty, and also by minor degrees of insuffi- 

 ciency in the internal secretions, which may not be 

 sufficient to delay the appearance of the secondary 

 characteristics ; for instance, we usually find that, when 

 there is deficiency of the internal secretion of the thyroid, 

 the uterus is well developed, if a little small, but that 

 menstruation does not occur. These cases are well 

 known, and they readily respond to treatment with 

 thyroid extract. 



