THE HIGHER BACTERIA 965 



shown bulbous or club-shaped ends. In Norris and Larkin's case, 

 the young cultures in the first generations seem to have consisted 

 chiefly of rod-shaped forms not unlike bacilli of the diphtheria group, 

 showing marked metachromatism when stained with Loeffler's 

 methylene-blue. They are easily stained with this dye or with 

 aqueous fuchsin. Many strains are acid-fast, but decolorize some- 

 what more readily than do tubercle bacilli. In tissue sections they 

 may be demonstrated by the Gram-Weigert method. 



Cultivation. The organism develops slowly on ordinary agar 

 or gelatin plates, forming visible colonies in from two to five days. 

 Later it forms a membrane somewhat adherent to the surface which 

 soon becomes wrinkled. It is at first white but later turns yellow 

 or even a brilliant orange. On broth they grow as a thick pellicle 

 or, occasionally as a flocculent precipitate. Most strains have not 

 liquefied gelatin or altered litmus milk, but liquefying strains have 

 been described. All strains have proved highly virulent for guinea- 

 pigs and somewhat less so for rabbits, producing in the animals 

 lesions indistinguishable from tuberculosis. 



NOCARDLE IN RAT-BITE FEVER. In the cases of fatal septicemia 

 following rat bites, Schottmueller 16 and Blake 17 have recovered 

 nocardias from the blood. It has since been shown, however, that this 

 disease is due to infection by treponemata. 



Streptothrix of Rosenbach. A species of nocardia undoubtedly 

 different from the asteroides group has been described by Rosen- 

 bach 18 as the cause of an indolent dermatitis of the fingers and toes 

 known as erysipeloid. 



ACTINOMYCES 



(Streptothrix Israeli, Kruse; Discomyces bovis, Brumpt ; Colmistrep- 

 tofkrix Israeli, Pinoy) 



Among the diseases caused by the Trichomycetes or higher bac- 

 teria, the most important is actinomycosis. Occurring chiefly in 

 some of the domestic animals, notably in cattle, the disease is 

 observed in man with sufficient frequency to make it of great clinical 

 importance. In cattle the specific microorganism which gives rise 



"Schottmueller, Dermat. Wchnschrft., 1914, LVIII, Sup. 77. 

 "Blake, F. G., Jour. Exp. Med., 1916, XXIII, 39. 

 18 Rosenbach, Arch. f. klin. Chirurg. 1887, xxiv, 346. 



