Mesothelium and Adhesions 



343 



ceived repeated injections of solutions of glucose, the mesothe- 

 lium undergoing certain changes of a morphological character 

 which were not followed by adhesions. It seemed important to 

 determine to what extent such changes could be produced with- 

 out sufficient injury occur ing to cause the development of ad- 

 hesions. Such experiments have been carried out by the repeated 

 introduction into the peritoneal cavity of various types of mild 

 irritants, the best results having been obtained with laked 

 heterogenous blood. Cats were given injections of 10 to 20 c.c. 

 of laked rabbit's blood made isotonic with XaCl, the dose being 

 repeated twice weekly over a period of 3 to 6 months. In such 

 animals when the procedures were carefully guarded to prevent 

 undue injury on puncture of the abdominal wall, and precautions 

 taken to avoid any septic involvement, there resulted very re- 

 markable changes in the entire mesothelial membrane without 

 the formation of a single adhesion. 



The peritoneum on section was often made up of two or 

 three layers of cuboidal or columnar cells, attaining at times a 

 thickness of 20 micra. and yet such a peritoneal lining seemed 

 entirely adequate to prevent the formation of adhesions. From 

 such observations the conclusion seems wholly justified that the 

 presence of a complete layer of peritoneal lining cells, no matter 

 how much their morphological appearance may be altered by 

 such irritations as those used, is entirely sufficient to prevent the 

 adherance of the two layers of peritoneum and thus prevent ad- 

 hesions. 



167 (2127) 



Note on the permeability of the placenta in the rabbit. 

 By R. S. CUNNINGHAM. 



[From the Department of Anatomy, The Johns Hopkins Univer- 

 sity, Baltimore, Maryland.] 



The observations of various anatomists have shown very 

 clearly that there are wide variations in the structure of the 

 placental barrier in such species as the ungulate, the carnivora 

 the rodentia, the chiroptera, and primates. Grosser 1 classifies 



i Grosser^ O., Vergleichende Anatomie und Entwicklungsgesehichte der 

 Eihaute und der Pacenta, Leipzig, 1909, "W. Braumiiller. 



