CHANGES IN NON-PREGNANT UTERUS 85 



A. Period of Rest. Stage I. The Resting Stage. 



TJ T> i e r< ( II- The Growth of Stroma. 



b. Period or Lrrowtn. TTT m, ^ e TT i 



I 111. ine Increase of Vessels. 



/ IV. The Breaking Down of Vessels. 



C. Period of Degeneration.^ ^ e Formation of Lacunae. 



| VI. The Rupture of Lacunae. 



V VII. The Formation of the Menstrual Clot. 



D. Period of Recuperation. VIII. The Recuperation Stage. 



Heape's account may now be briefly summarised. 



I. The Restimj Stage. The epithelial layer of the uterine mucosa 

 consists of a single row of cubical or columnar cells. The outer 

 border is clearly defined, but on the inner side the protoplasm of 

 the epithelium is continuous with that of the sub-epithelial mucosa 

 or stroma tissue. The surface epithelium is continuous with that 

 of the glands, but the latter rest on a basement-membrane which 

 separates them from the interglandular stroma. The stroma contains 

 round nuclei embedded in a network of protoplasm, with fine, delicate 

 processes in which granules may be seen. In Semnopithecus fibrils 

 running fan-wise were observed in the deeper parts of the stroma, 

 but these were not seen in Macacits. Multiplication of cells was not 

 noticed at this stage, either in the epithelium or in the stroma. The 

 vessels in the mucosa are small. A few arteries occur in the deeper 

 portion, but only thin-walled capillaries in the more superficial part ; 

 the latter, however, are fairly numerous. 



II. The (Irutcth of Stroma. The nuclei of the more superficial 

 part of the stroma undergo a great increase, the division being 

 amitotic in character, at least so far as could be seen. As a con- 

 sequence the mucosa in its upper third becomes considerably swelled 

 (hyperplasia), but in the deeper portion there is no change in the 

 tissue. Owing to the effects of pressure the nuclei become elongated 

 or fusiform. Division occurs either by fragmentation or by the 

 nucleus simply splitting into two. The growth in the upper part 

 of the stroma is associated with an increase in the size of the blood- 

 vessels in the deeper part. The superficial epithelium, and also the 

 epithelium of the glands, remain practically unchanged. 



III. The Titr/raxe of Vessel*. Owing to the continued swelling of 

 the stroma the nuclei in the superficial portion are packed less 

 densely, the lining epithelium becoming simultaneously stretched. 

 The glands tend to become wider. Hyperplasia of the vessels occurs 

 below the epithelium, the surface of the mucosa appearing Hushed. 

 At the same time leucocytes become more numerous within the 

 vessels. There is no change in the constitution of the deeper portion 

 of the stroma. 



IV. 7'/t>- Urmking l)/,ir,i ,,/' l'< Wx. The whole of the mucosa, 



