254 BACTERIA, 



bone in the cervical and dorsal vertebrae. Those who had 

 examined the condition only in the human subject and in the 

 pig describe the disease as consisting essentially of a sup- 

 purative process, whilst those who have examined " wooden 

 tongue " in cattle, and " scirrhous cord " of the horse, maintain 

 that the process, though sometimes leading to softening, is 

 essentially of the granuloma or new young tissue formation 

 type. These differences, however, appear to be due rather 

 to the nature of the tissues in which the growths occur than 

 to any difference in the character of the organism that 

 produces them, for it is found that in many cases in which the 

 bones are attacked in the cow the lesion takes on a suppura- 

 tive character. It was, however, the non-suppurative form 

 that was first described, and it will therefore be better to 

 examine it in the first instance. In " wooden tongue " of 

 the ox, on superficial examination, firm hard points may be 

 seen scattered over the surface, varying in size from that of a 

 millet seed to that of a split pea. On incising one of these, 

 it is found to be firm and fibrous at the periphery and especi- 

 ally in the small nodules ; the centre may be soft but not 

 purulent, or, rarely, gritty and almost calcareous ; in the larger 

 nodules little fibrous bands running through them form a kind 

 of net-work, and in the centre of each mesh is a similar 

 soft point. If this softened caseous point be removed with 

 the point of a knife and examined under the low power of 

 the microscope ( x 50) it will usually be found to contain, 

 embedded in a small mass of cells, a small core, which by 

 transmitted light is yellow or brownish in colour, dashed 

 with a tinge of green. This little mass is seen to be com- 

 posed of a kind of star made up of a number of wedge- 

 shaped rays, the apices of the wedges meeting in the 

 centre, the bases being rounded ; looking down on the 

 centre of this cord it appears as though there are 

 rounded instead of wedge-shaped bodies (this is simply 

 because we are looking down on the rounded ends of the 

 wedges). If now one of the " bony " tumours, or one of the 

 tumours in the fibrous covering of the bone, where the 

 tumours are usually of larger size, be examined, it will be 

 observed that the fibrous net-work is exceedingly well marked, 

 especially as on section the softened caseous centre gives way 

 very readily : in the softened material similar " rayed " or 

 star-like organisms may be found. In the material that is 



