INNERVATION OF THE GENERATIVE ORGANS 581 



estimated it as 10^ ounces (or considerably less than Gassner's 

 estimation), and found further that in women who were accustomed 

 to bleed freely at the menstrual periods the amount of the lochial 

 discharge was beyond the average. According to Gassner, the 

 discharge is generally less in women who suckle. 



The uterus after delivery becomes rapidly reduced in size. This 

 process is known as the involution of the uterus; it is completely 

 effected in from five to eight weeks, the greatest reduction taking 

 place in the first few days. Thus the freshly delivered uterus weighs 

 on an average 1000 grammes (or about two pounds), a week later it 

 weighs only half that amount, at the close of the second week 375 

 grammes, and at the end of the puerperal period as little as 

 60 grammes (or about two ounces). Its decrease in size is such that 

 by the tenth day after parturition the organ is once more confined 

 to the cavity of the pelvis proper, and cannot be felt above the 

 symphysis. 



The process of uterine involution is the result chiefly of changes 

 occurring in the muscle walls.^ The size of the individual cells 

 becomes very markedly diminished, but there is little or no reduction 

 in their number. Fatty degeneration does not take place in the 

 muscular tissue. It is stated that the retraction of the muscle fibres 

 produces a compression of the vessels, and that the comparatively 

 ,anaemic condition of the puerperal uterus, especially in the earlier 

 stages, is due to this cause. Subsequently the uterus becomes more 

 vascular again. 



The remains of the decidua which are not expelled at parturition 

 undergo degeneration and are discharged in the lochia, leaving only 

 the fundi of the glands and a certain amount of connective tissue 

 from which the uterine stroma is renewed. The epithelium is 

 re-formed from that of the glands, as shown by Friedlander,^ Kundrat 

 and Engelmann,^ Leopold,* Kroni^ and others.^ Excepting in the 

 position of the placenta, the new epithelium is completely regenerated 

 by the end of the sixth week after delivery. 



' The account given of the changes in the uterus during the puerperium is 

 based largely on that given by Williams {Obstetrics, New York, 1904). See 

 also Sellheim, "Das Wochenbett," in Nagel's Haridbuch der Physiologie des 

 Mensohen, vol. ii., Braunschweig, 1906, where further references are given. 



2 Friedlander, Physiologische mid Anatomisohe Untersiwhungetp, ilher den 

 Uterus, Leipzig, 1870. 



3 Kundrat and Engelmann, " Untersuchungen iiber die Uterusschleimhaut," 

 Strieker's Med. Jahrbiich, 1873. 



* Leopold, Studien iiber die Utemsschldmhawt, etc., Berlin, 1878. 



^ Kronig, "Beitrag zum anatoniischen Verhalten der Schleimhaut der Cervix 

 und des Uterus, etc.," Arch. f. Oyndh., vol. Ixiii., 1901. 



" Leusden, assuming the syncytial tissue of the deciduum to be of maternal 

 origin, has suggested that it may assist in giving rise to the new epithelium 

 (" Ueber die Serotinalen Eiesenzellen, etc.," Zeitsch.f. Geb. imd Oyndk, vol. xxxvi., 

 1897). 



