i HI: i OR M HI. -"'"' 



ordinary abundance of cell \\ Inch are >pindlc->ha| e I. others 



roundish. 



r'rom the beginning of pregnancy the mucous membrane undergoes 

 very profound changes, \\hich a Meet all j .ncerning these we 



possess accurate ohser\ ai inns, which relate to every in mtli of preg- 

 nancy, by KiNDKAT UND K\< ; i:i.\i A N \ . as well as by LKol'ni.D and 



W|< K .M I NOT. 



We take up in succession (1) tin- decidua vera. ( '2 ) the decidua 

 rellexa, and (3) the decidua semtina <>r placcntalis, tin- part which 

 riitrrs into the formation of the placenta. 



(1) Decidua vera. As LEOPOLD remarks, with tin- beginning of 

 pregnancy the mucous membrane constantly increases in thickness, 

 until it becomes 1 cm. or more thick, up to the time, indeed, when 

 the irnmini: ovum attaches itself completely to the walls of the 

 uterus, therefore approximately up to the end of the fifth month. 

 From that time forward there begins, as it were, a second stage, in 

 whirli. under the pressure of the growing foetus, it again becomes 

 thin and finally is only 1 to 2 mm. thick. Meanwhile both the 

 glands and the tissue between them undergo changes. 



During the Jirst staye the (> m<>> 'jlnn-lx, which at the beginning 

 are tubes of uniform calibre, 'mmiM in size, especially in their 

 middle and deeper parts (tig. 14G); whereas at their open end- 

 they are rectilinear and drawn out lengthwise, deeper down 

 they take a spiral course and are covered with evaluations and 

 pocketings. 



Upon sections therefore one can now distinguish two layers in the 

 decidua vera : 



(1) An outer more compact layer ((7), possessing more abundant 

 cells, and 



A deeper ampullar or spongy layer (Ny). 



In t lie form er one sees the glands as elongated, parallel canals. 

 In consequence of a great growth of the inter-tubular tissue they 

 are separated from one another farther than at tir>; : they begin at 

 the surface with enlarged funm'1-shniml /n'fft (//). Tin- surface of a 

 mucous membrane stripped off from the musculature has, M KOU.IKKK 



states, a sieve-like appearance, due to the ei darned rilices of tlie irlands. 

 In the tijnnit/1/ latfer (Sp) one encounters irregular, lobed 

 cavities (,//,) one above another, the capacity of which continually 

 increases up to the middle of pivirnaney. and which are finally 

 ated from one another by thin -enta and cord* of the matrix- 

 tissue only. The appearance is explained by the fact that in the 



