426 SUMMARY OF OURBENT RESEARCHES RELATING TO 



The micrococci are best detected by placing the cover-glass with 

 the dried-up fluid, coloured by aniline-water and gentian-violet solu- 

 tion, in a watch-glass with alcohol for half a minute, when the matrix 

 rapidly loses its colour, the envelopes and micrococci much more 

 slowly. The preparation may then be placed in a watch-glass with 

 distilled water, examined in water, and afterwards preserved in 

 Canada balsam or dammar lac. The envelopes are also coloured by 

 eosin, especially by a weak solution acting for twenty-four hours ; 

 osmic acid differentiates them sharply, but without blackening them. 

 These envelopes appear to be a highly characteristic peculiarity of 

 the micrococci of pneumonia, never failing in acute genuine cases. 

 They probably belong to the acme of that disease, not being found 

 after the sixth day. 



If developed by Koch's process on serum of blood and afterwards 

 on gelatine, with addition of infusion of flesh, peptone, and sodium 

 chloride, the micrococci have on serum of blood the form of a greyish 

 pellicle on the surface, and an opaque cylinder in the interior of the 

 serum. The cultures on gelatine were especially characteristic, and 

 were propagated for eight generations. They resembled a nail with 

 hemispherical head, and consisted of densely crowded micrococci, 

 usually of elliptical form, but with no envelope. They were also 

 cultivated on potato. 



Experiments were also made in inoculating the pneumonia-micro- 

 cocci in animals, by injection into the right lung. With rabbits no 

 success was obtained ; while mice always died in from 18 to 28 hours. 

 In the cavities of the pleura, partly in the fluid, partly in the lymphoid 

 cells, were masses of micrococci, with all the characters of those of 

 pneumonia, including the envelope. They were also found in the 

 lungs and blood. With dogs and porpoises no result was obtained 

 in some cases, while others were successful. Experiments were also 

 made with mice by inhaling ; when some only were infected. 



The size of the micrococci and development of the envelopes differ 

 considerably with men and other animals. Those of mice were, on the 

 average, larger than those of man ; those of porpoises were smaller, 

 but with broader envelopes ; those of dogs were scarcely larger than 

 those of man, and the envelope comparatively narrow. The mode of 

 preparation also has an influence on the size of the micrococci. 



Bacteria of the Cattle Distemper.* — The bacterium of the cattle- 

 distemper has been hitherto known almost exclusively in the bacillus 

 condition, not making its appearance in the blood till some ten hours 

 before the death of the animal. F. Eoloff has examined the blood in 

 the early stages of the disease, and also those organs, especially the 

 spleen and the lymphatic glands, in which the bacilli are first seen. 

 In all these he found a large number of small round shining bodies 

 or micrococci. The infection of other animals with blood containing 

 these cocci, produced in them the ordinary distemper with its bacilli, 

 showing that the two are stages of development of the same organism. 



* Arch. Wiss. u. Prakt. Thierheilkunde, ix. (1883). See Bot. Centralbl., xvii. 

 (1884) p. 112. 



