CHANGES IN THE NON-PREGNANT UTERUS 95 



The nuclei which were hypertrophied become reduced in size, 

 and the swollen protoplasm becomes contracted. In this way 

 the vessels are reduced once more to their normal size. 



(4) The changes in the cells of the stroma are described as 

 being similar to those in the cells which form the walls of the 

 hypertrophied vessels, the large nuclei and swollen protoplasm 

 giving place to compact nuclei and fine thread-like processes of 

 protoplasm. The multiplication of the stroma nuclei still goes 

 on to a limited extent, but is not nearly so frequent. The tissue 

 is very open during the early stages of recuperation, but 

 gradually becomes drawn together. As a result the whole 

 stroma is reduced considerably in bulk. 



(5) The extravasated leucocytes, like the red corpuscles, are 

 said to be returned into the circulatory system by means of 

 the newly formed vessels. Heape says that isolated wandering 

 leucocytes are very rare indeed at this stage, and he makes no 

 mention of basophil or eosinophil cells, such as have recently 

 been described in the uterus of the dog. The actual proportion 

 of leucocytes within the vessels is said to be greater than at any 

 other period in the cycle, as many as fifty per cent, having been 

 observed in certain of the vessels. With regard to the function 

 of the leucocytes Heape suggests that in cases of suppressed 

 menstruation they might play an important part, but that in 

 normal menstruation " they seem to have been induced to 

 appear on the scene in such numbers, unnecessarily ; the casting 

 away of the menstrual inucosa, together with all noxious material, 

 and the clean healing of the wounded surface, rendering their 

 protective presence unnecessary." At the same time Heape 

 points out that the presence of the leucocytes in the vessels is 

 evidence of the existence therein of a noxious substance which 

 is not present in the surrounding tissue, and he supposes that 

 this irritant may be got rid of completely in the flow of blood. 



Menstruation in Macacus has also been studied by Bland 

 Sutton, 1 according to whom the sanguineous discharge is slight. 

 Button found no evidence of destruction of the uterine mucosa, 

 not even of the epithelium, but the uterus was distinctly con- 

 gested, and there was an escape of blood into the cavity. It 



1 Bland Sutton, "Menstruation in Monkeys," Brit. Gymec. Jour., vol. ii. 

 1880. 



