OKLAHOMA ACADEMY OF SCIENCE 33 



XVI. FATE OF LEUCOCYTES IN THE PLACENTAL CIR- 

 CULATION. I. WHAT PREVENTS LEUCOCYTES OF 



THE MATERNAL CIRCULATION FOM MIGRATING 

 INTO THE FETAL CORCULATION? II. THE ROLE 

 OF THE SYNCYTIAL LAYER OF THE CHORIONIC 

 VILLI. III. IMPORTANCE OF THIS INVESTIGA- 

 TON RELATIVE TO INHERITANCE OF DIS- 

 EASE OR IMMUNITY FROM DISEASE 

 Jos. M. Thuringer. 

 From the Laboratoi"}' of Histology of the University of Oklahoma. 



A. The question arises whether or not leucocj^tes wander from 

 the maternal blood sinuses in the placenta thrugh the chorionic villi 

 into the fetal circulation. Experiments were carried on with a 

 series of white rats on the twelfth day of gestation. A colloidal 

 carbon solution was injected into the tail vein of the rat. ' In half 

 an hour the animal was killed, the abdomen opened, the uterus re- 

 moved and transferred to Bouin's fluid or Zenker's fluid in toto. 

 Paraffin section 5 micra in thickness, stained with the routine 

 liematoxylon eosin stain, showed numerous polymorphs, containing 

 carbon granules, in tlie maternal sinuses but none have been 

 found on the fetal side of the circulation of in process of transmi- 

 gration. 



B. The syncytial layer seems to form a definite ])arrier as 

 there were several instances encountered in which a nmnlier of 

 carlxju-granule bearing leucocytes vvcre in immediate contact with 

 •his layer apparently una]):e to pass beyound. 



A-dditicnal experiments are now in progress, partly for the pur- 

 pose of confirming the above results and also to show under what 

 circumstances, if any, leucocytes may vv^ander from the m.aternal 

 into ihe fetal circulation. 



XVII. A NEW DIFFERENTIAL STAINING METHOD 

 FOR CONNECTIVE TISSUE COMBINED WITH THE 



ORDINARY HEMATOXYLIN-EOSIN STAIN 

 (Demonstration) 

 Jos. M. Thuringer. 

 F'rnrn the Laboratory of Histology of the Uniyer.sit}- of Oklahom.a. 

 Material fixed in Zenker's or Helley's fluid is used. Paraffin 

 or celioidin section are stained rather deeply in any good hema- 

 toxylin then differentiated in 2 1-2% acetic acid for one minute or 

 longer depending upon the intensity of the hematoxylin stain. After 

 this the sections are passed through the usual 1-2 of 1% watery 

 cosin in 25'/f alcohol, then 1-2 of 1% Orange-G in 95% alcohol, 



