MENSTRUATION. 569 



ation, yet it is more likely to occur within a few days after the 

 cessation of the menstrual flux than at other times ; and, lastly, 

 that the ovaries of the human female become turgid and vas- 

 cular at the menstrual periods, as those of animals do at the 

 time of heat. 



From what has been said, it may, therefore, be concluded 

 that the two states, heat and menstruation, are analogous, and 

 that the essential accompaniment of both, is the maturation 

 and extrusion of ova. In both there is a state of active con- 

 gestion of the sexual organs, sympathizing with the ovaries at 

 the time of the highest degree of development of the Graafian 

 vesicles; and, in both, the crisis of this state of congestion is 

 attended by a discharge of blood or mucus, or both, from the 

 external organs of generation. 



The occurrence of a menstrual discharge is one of the most 

 prominent indications of the commencement of puberty in the 

 female sex ; though its absence even for several years is not 

 necessarily attended with arrest of the other characters of this 

 period of life, or with inaptness for sexual union, or incapabil- 

 ity of impregnation. The average time of its first appearance in 

 females of this country and others of about the same latitude, 

 is from fourteen to fifteen; but it is much influenced by the 

 kind of life to which girls are subjected, being accelerated by 

 habits of luxury and indolence, and retarded by contrary 

 conditions. On the whole, its appearance is earlier in persons 

 dwelling in warm climes than in those inhabiting colder lati- 

 tudes; though the extensive investigations of Mr. Roberton 

 show that the influence of temperature on the development of 

 puberty has been exaggerated. Much of the influence attrib- 

 uted to climate appears due to the custom prevalent in many 

 hot countries, as in Hindostan, of giving girls in marriage at 

 a very early age, and inducing sexual excitement previous to 

 the proper menstrual time. The menstrual functions continue 

 through the whole fruitful period of a woman's life, and usually 

 cease between the forty-fifth and fiftieth years. 



The several menstrual periods usually occur at intervals of 

 a lunar month, the duration of each being from three to six 

 days. In some women the intervals are as short as three weeks 

 or even less; while in others they are longer than a month. 

 The periodical return is usually attended by pain in the loins, 

 a sense of fatigue in the lower limbs, and other symptoms, 

 which are different in different individuals. Menstruation 

 does not usually occur in pregnant women, or in those who 

 are suckling ; but instances of its occurrence in both these con- 

 ditions are by no means rare. 



The menstrual discharge consists of blood effused from the 



