CHAP. XXXIX.] MENSTRUATION. 561 



enlarge and an increased deposit of fat takes place over the sur- 

 face of the body generally. The most important indication, how- 

 ever, of puberty, or aptitude for procreation, in the human female, 

 is the appearance of the catamenia. Nevertheless, instances have 

 occurred in which the menstrual secretion was retarded for several 

 years, or even in which it never appeared, although the suscepti- 

 bility for procreation existed, and impregnation had taken place. 

 Hence, although the presence of the menstrual discharge indi- 

 cates that the period of puberty has arrived, its absence cannot 

 be looked upon as a proof of the want of procreative power; 

 while, in some instances, the catamenia may appear regularly 

 without impregnation ever taking place, in consequence of certain 

 abnormal conditions of the organs of generation. The period of 

 puberty is more affected by the habits of the individual than by 

 temperature, although the latter probably exerts some slight influ- 

 ence. In Africa, menstruation is said to be common as early as 

 the eighth or ninth year; but in colder climates, and in our 

 own country, it seldom occurs before the thirteenth year, and 

 usually not until the fifteenth or sixteenth' year. Still cases are on 

 record in which the catamenia appeared in young children in 

 this country ; and their apparance was marked by enlargement of 

 the breasts, and other changes indicative of puberty. 



In both sexes, the period of puberty is much influenced by the 

 conditions under which the child is placed. Habits of indolence, 

 luxury, and indulgence, tend to the early development of puberty 

 while, on the contrary, it occurs some years later in those who are 

 inured to active employment, and who are placed under condi- 

 tions favourable for promoting bodily vigour and mental activity. 



The catamenia occur at intervals of a month, and the discharge 

 usually continues from three to six days. It ceases during preg- 

 nancy and lactation, and, in most women, does not recur after the 

 forty-fifth to the fiftieth year ; but exceptions to these statements 

 are met with from time to time. 



At each menstrual period, the mucous membrane of the uterus, 

 and of the generative organs generally, becomes turgid, in conse- 

 quence of an increased local determination of blood. The mucous 

 surface of the uterus is covered by a sanguineous discharge, which 

 escapes from the turgid vessels. 



Of the Menstrual Fluid. The quantity of the menstrual secretion 

 varies considerably, as also do its characters. In this country, 

 from four to eight ounces are lost at each menstrual period, but 

 sometimes the quantity is much greater. It is of a dark red colour 



