454: GENERATION. 



seldom later than eight days after parturition, the uterus has 

 sensibly advanced in the process of involution ; and it is then 

 gradually reduced to the size and structure which it presents 

 during the non-pregnant condition, though it never becomes 

 quite as small as in the virgin state. The new mucous mem- 

 brane, which has been developing during the latest periods of 

 pregnancy, becomes perfect at about the end of the second 

 month after delivery. It has then united, at the os inter- 

 num, with the mucous membrane of the neck, which does 

 not participate in the formation of the decidua. The mus- 

 cular fibres, after parturition, present granules and globules 

 of fat in their substance, and are gradually reduced in size, 

 as the uterus becomes smaller. Their involution is com- 

 plete at about the end of the second month. During the 

 first month, and particularly within the first two weeks 

 after delivery, there is a sero-sanguinolent discharge from 

 the uterus, which is due to disintegration of the blood and 

 of the remains of the membranes in its cavity, this debris 

 being mixed with a certain amount of sero-mucous secretion. 

 This discharge constitutes the lochia, which are at first red, 

 but become paler as they are reduced in quantity, and disap- 

 pear. 



During lactation, which we have already considered in 

 another volume, 1 the processes of ovulation and menstruation 

 are usually arrested, though this is not always the case. In the 

 volume on secretion, we have given a full description of the 

 vernix caseosa, and, in the same volume, we have stated what 

 is known with regard to the properties and composition of 

 the urine of the foetus. 2 



Meconium. At about the fifth month, there appears a 

 certain amount of secretion in the intestinal canal, which be- 

 comes more abundant, particularly in the large intestine, as 

 development advances. This is rather light-colored or gray- 

 ish in the upper portion of the small intestine, becoming yel- 



1 See vol. Hi,, Secretion, p. 72, et seq. 2 Ibid., pp. 67, 221. 



