248 BACTERIA. 



time considered to be spores are not spores at all, but are 

 appearances due to the alterations that have taken place in the 

 protoplasm during the processes of preparation and staining. 

 As it is not yet certain that the bacilli can be cultivated, little 

 evidence either for or against the spore theory can at present 

 be adduced. These bacilli, to be seen in their characteristic 

 form, should be examined as they lie in the thickened nodules 

 of the skin or in the mucous membrane of the mouth and 

 larynx, in the thickened nerves, in the lymphatic glands, in 

 the spleen, or in the liver. If a thin section be made of a 

 nodule of the skin, and the specimen be stained with fuchsin, 

 and decolorized with a mineral acid, and a contrast stain 

 of methylene blue be obtained (see Appendix), it will be 

 found that, throughout the section, branching lines or small 

 rounded points of bright red may be seen on a blue back- 

 ground ; these bright red areas are nothing but masses of 

 leprosy bacilli which fill the lymphatics of the skin, and, as 

 one would expect, interfere very seriously with its nutrition. 

 There seems to be a considerable difference of opinion as to 

 whether these bacilli actually invade the cells or whether 

 they lie free in the lymph channels ; there can be no doubt 

 that a very large number of them ultimately are seen as free 

 bacilli lying in these spaces, the difference of opinion being 

 as to the nature of the so-called u lepra " cells. There are 

 usually found in cases of leprosy a number of large proto- 

 plasmic masses, which are said to be multi-nucleated, and 

 are spoken of as giant cells, and in these are found numerous 

 bacilli. In younger nodules there are smaller masses of 

 protoplasm, in which nuclei and bacilli may be distinctly 

 seen. At the meeting of the British Medical Association, 

 held in Dublin in 1887, Dr. Unna, of Hamburg, placed 

 before the members his views on many of these so-called 

 lepra cells. He contended that the rounded outline was 

 due in many cases to the form of the lymphatics, and he 

 showed in his specimens that the rounded section was equal in 

 diameter to the longitudinal section of one of these lymphatics 

 filled with bacilli ; that the longitudinal section proved that 

 we have here to deal simply with a lymph channel blocked 

 with leprosy bacilli, and therefore that the rounded masses 

 are merely transverse sections of these stuffed lymph chan- 

 nels. He also maintained that these so-called cells, with 

 their contained bacilli, were merely masses of these organisms 



