GROWTH AND REPRODUCTION 



777 



enzymes within the uterine wall, 

 within three months. 



It is a rapid process, and is complete 



Serum Test for Pregnancy. 'Recently there has been devised a 

 serum test for pregnancy. It is based upon the view that during 

 pregnancy the maternal serum acquires the power of digesting the 

 " specific " albumin which passes into the circulation from the placenta. 

 In order to test if a subject be pregnant, the blood-serum of the sub- 



vein 



artery 



artery 



muscular coat 

 blood spaces 

 vein 



chorionic uilius 

 decidua serotina 



chorion 

 ammon. 



decidua uera 



decidua reflexa 



ceru/x 



FIG. 485. SHOWING ARRANGEMENT OF THE AMNION, CHORION. AND DECIDUA IN 

 THE THIRD MONTH, AND THE FORMATION OF THE PLACENTA. (Keith.) 



ject is added to specially prepared placental tissue placed in a dialyzer. 

 If the tissue is digested and amino-acids pass through the dialyzer, 

 it is deemed a sign of pregnancy. Normal serum is stated not to have 

 such digestive powers. It is true that the test is more often positive 

 in the pregnant than in the non-pregnant, but the test is by no means 

 certain, and it is said that by it even males are occasionally reported 

 to be pregnant. 



