474 BIOLOGICAL PHYSICS 



physiological limits ; and for an illustration of this con- 

 tention, let us take the most prominent and outstanding 

 example with which we have to deal in the human species, 

 viz. the child-bearing period, and organs of reproduction, 

 proper and subsidiary, of the female. The period of 

 time embraced by the active functional working of these 

 organs is represented by the years intervening between 

 the age of puberty and the attainment of the menopause, 

 and is of variable duration, due to the operation both of 

 individual and general or climatic causes. During its 

 continuance, great fluctuations, both in evolutionary and 

 involutionary change, ensue from the exigencies of mater- 

 nity a consequent loss, or lapse, of parallelism preceding 

 and accompanying them, especially the latter which is 

 the cause of many of the gynaecological ailments which 

 ensue during this period of life, the rectification of which 

 can best be effected on the lines thus indicated. In this 

 connection we would observe that it is most remarkable, 

 however, how often the human female, and more especially 

 that of the fer<e nature, performs the function of mater- 

 nity, with absolute freedom from untoward circumstances, 

 during any and every period of its duration so precise 

 and self-sufficient are the provisions of nature in all their 

 details, a fact which warrants us in closely copying her 

 methods and designs and adopting her plans, when called 

 upon, in the exercise of our profession, to deal with such 

 matters. 



The cessation of the function of reproduction, and 

 especially the attainment of the menopause, mark a 

 period when a lapse of involutionary parallelism between 

 structure and function may, and not infrequently does, 

 take place, and where the lapse of function is, or may, 

 for a variable period, be followed by a more or less 

 appreciable continuance, or survival, of structure. Should 

 this disparity be considerable in amount or extent, or 

 long continued, the result will be a pathological condition, 

 proportionate in extent, continuation, and intensity to the 

 disparity. This doctrine applies equally to the uterine 

 and mammary organs and subsidiary textures, and also 

 applies with peculiar force to the incidence of disease in 

 all organisms whose developmental history is one of 



