Immunity of the skin and mucous membranes 429 



tinual and normal condition is often termed Stohr's phenomenon. 

 It is evident that we have here a process of phagocytic defence in 

 which the leucocytes, disseminated through the digestive canal, give 

 chase to the micro-organisms that are nearest to the living portions 

 of this organ. When we remove a particle of mucus from the 

 surface of the tonsils of a person in good health we always find 

 that it contains leucocytes, especially microphages, filled with 

 micro-organisms of all kinds. 



The protection of the digestive mucous membrane is a more 

 complicated process than that of other mucous membranes, and many [450] 

 of the points concerned therein are still obscure and need to be 

 elucidated by further research. It might be thought that the pheno- 

 mena, associated with the defence of the mucous membrane of the 

 genital organs, being much more simple and yet of similar nature, 

 should be much more easily made out, and that these would throw 

 light on several aspects of the problem of the general defence of 

 the animal. Obstetricians and gynaecologists have certainly given 

 much attention to this question as regards the female genital organs, 

 but we are still far from possessing a satisfactory knowledge of this 

 subject. There already exists quite a literature on the question, 

 dominated by the work in two volumes published by Menge and 

 Kronig 1 , but a satisfactory solution has still to be obtained. 



At birth the vulva and the vagina are free from micro-organisms, 

 but they soon become inhabited and a fairly abundant flora, in 

 which may be recognised certain predominant species, such as the 

 bacillus of Doederlein, is developed. Micro-organisms, therefore, 

 can exist in the vulva and the vagina, and yet, when we intro- 

 duce into these organs cultures of various bacteria, saprophytic 

 or pathogenic, they soon disappear. We have the phenomenon to 

 which Menge has given the name of " autopurification " of the female 

 genital organs. He himself, as well as his predecessors, Doederlein 

 and Stroganoff, tried to make out the mechanism of this purification. 

 In the new-born female child the phenomenon is less complicated 

 than in the adult. According to Menge the acidity of the vaginal 

 secretion in these infants at first prevents the development of a 

 large number of bacteria. Associated with this factor is a marked 

 emigration of leucocytes, which destroy the bacteria by an act of 

 phagocytosis, or perhaps by their products that have escaped into 

 the vaginal mucus. As a third element to which much importance 

 1 " Bakteriologie des weiblichen Genitalkanals," Leipzig, 1897. 



