438 M. AEMAND EUPFER. 



or in the deep layers of the tissue. The whole process^ there- 

 fore; as far as the bacilli are concerned, takes place on the 

 surface of the false membrane and nowhere else. 



Shortly stated, the false membrane consists of a reticulated 

 network of fibrin, containing within its meshes a large number 

 of wandering cells, some of which are healthy, whilst others 

 have undergone a distinct process of degeneration. I must draw 

 attention to the fact, however, that the wandering cells present 

 in the membrane are of two kinds; some smaller and mono- or 

 multi-nucleated (microphages), and others, less numerous, much 

 larger, with a single, clear, vesicular nucleus (macrophages). 



Many of the leucocytes which have penetrated between the 

 bacilli are quite empty ; but others, especially those in the 

 layer of the false membrane close to the thick layer of bacilli 

 previously described, contain one, two, or more diphtheritic 

 bacilli (fig. C, a, b), as many as five or six micro-oi'ganisms 

 being sometimes enclosed in one cell. Some of these intra- 

 cellular bacilli appear to be healthy, staining and retaining 

 colouring matters well; whilst other micro-organisms also 

 contained in amoeboid cells show signs of degeneration, varying 

 from a mere difference in the power of retaining gentian - 

 violet to complete disorganisation and destruction (see fig. 

 E, a, h, c, d, ej,g). 



Many amoeboid cells in the membrane, more especially 

 those present in its superficial part, show distinct necrotic 

 changes, many of them losing the power of retaining colouring 

 matter. The nucleus breaks up, and does not stain at all, 

 even with strong logwood or carmine, the surrounding proto- 

 plasm swelling up, becoming more yellow, and not unfre- 

 quently vacuolated. In later stages they show distinct signs 

 of breaking up. Many of the degenerated cells contain bacilli 

 in their interior, whereas others are quite empty. 



Those lying between the cells in the fibrin and coagulated 

 exudation fluid are, for the most part, quite normal to all 

 appearance. Occasionally, though very rarely, one is met 

 with presenting signs of degeneration similar to those found 

 in the bacilli contained in amoeboid cells. I do not think it 



