BACILLUS SYCOSIFEEUS FGETIDUS 231 



medium (fig. 86). A surface-culture on agar likewise shows 

 roundish colonies, prominent in the centre. Those on serum 

 are ribbon-like with jagged edges, and do not cause lique- 

 faction. Cultivation experiments are best carried on at 

 37 C. 



The disease can be transmitted to men and animals. 

 In the tissues, the bacilli are found in the cutaneous con- 

 nective tissue, nerve-sheaths, spleen, and lymphatic glands, 

 but do not occur in the blood. According to Unna they 

 are found in the lymph-paths of the tissue, and he also 

 believes the lepra cells to be transverse sections of lymphatic 

 vessels. 



The other methods of staining the micro-organisms of 

 the epidermis, which can also be used for abscesses in 

 the skin, have already been dealt with in the general section, 

 to which the reader is referred (p. 90). 



Bacillus sycosiferus fcetidus was found by Tommasoli 

 on the hairs of the beard of persons suffering from sycosis. 

 The rods are short, rounded at the ends, and immotile, 

 and do not liquefy gelatine. Growth makes slow progress 

 at room temperature. On plate-cultures white punctate 

 colonies form, and gradually spread out like a slimy veil. 

 A white nail-head growth appears in thrust-cultures, and a 

 .greyish-white veil-like layer in surface-cultures on agar, 

 this being formed by the coalescence of single isolated 

 specks, and often showing wavy stripes. The colonies 

 on potato are raised, and coalesce with the formation of a 

 yellowish-white colour. Pure cultures may be obtained 

 from plucked-out hairs or from the pus in a bacillary sycosis ; 

 and if, on the other hand, some of a pure cultivation be 

 rubbed on the skin, there result reddening and intense 

 itch, and vesicles form in the neighbourhood of the hair. 



Ascobacillus citreus. This was found by Unna and 

 Tommasoli in cases of eczema of the skin, and consists of 



