40 THE MUCOUS MEMBRANE ELEVATION. 



regarding the first relation between the surface of the ovum and 

 the vascular system of the maternal mucosa. This relation is 

 established very early, both in the insectivora and the rodents. 

 The ectoblast thickens at the placental site by the formation of 

 numerous layers and lacunae soon form which become filled with 

 maternal blood. The manner in which the blood gains access to 

 these spaces is not sufficiently understood, but it is certain that 

 the new formation of maternal blood vessels near the ectoblast 

 is enormous and that from them the ectoblast lacunae receive their 

 blood supply." 



"The maternal blood from the very beginning remains in a 

 closed channel and in regular circulation. Frommel has demon- 

 stated the same conditions in the bat. In the carnivora, e. g., the 

 cat, these maternal vessel walls are also preserved in the pla- 

 centa. The significance of this fact for human placentation is 

 evident. In animals the "intervillous" spaces appear very early; 

 they are filled with blood from the very beginning and are in con- 

 stant and lasting communication with the maternal blood vessels. 

 These same conditions no doubt also prevail in the human." 



From the above description this presumption is proved a cer- 

 tainty, even for the earlier stages of the human ovum. ' 



The vascularity of the mucosa in my specimen, in its relation 

 to menstrual conditions, is still another subject worthy of 

 consideration in this chaper 



.Peters estimates the age of his ovum as from 3 to 4 days by 

 assuming a relation between it and the menstruation which for 

 the first time had just failed to appear. He bases his assump- 

 tion on the history of the case and on the histological condition 

 of the decidua, which, "in every respect resembles the description 

 given of decidua menstrualis immediately preceding menstrua- 

 tion." 2 



From the history Peters endeavors to show that on the day of 

 her suicide (October 1st) the pregnant woman was about to 

 menstruate. From the state of development of the Eianlage and 

 the entire ovum itself, no other conclusion could be drawn, save 

 that this represented the impregnated ovum of the expected men- 

 struation. Based on these facts he estimated the age of the 

 ovum as possibly three to four days. 



Although I agree with Peters in regard to the manstruation- 

 like appearance of the mucosa, I cannot coincide with him in his 

 calculations from the history of the case. 



We read' on page 3 of Peters' work that the woman had her 

 last normal menstruation on September 1st, 1895. At the end 

 of September (on September 28th, according to the normal type, 



1 Pfannenstiel 1. c. pg. 200. 



2 Peters 1. c. pg. 16. 



