36 THE GROUSE DISEASE chap. 



and stained in methyl blue or gentian violet, 

 washed in water, dried, and mounted. Examined 

 under the microscope, it shows the outlines of the 

 air-cells marked by innumerable microbes: round or 

 oval forms, singly and particularly in dumb-bells, 

 rods singly and in dumb-bells, and a few cylindrical 

 forms (Figs. 13 and 14). In some cases their 

 number is not so great, but in acute fatal cases they 

 are always easily discovered in cover-glass specimens 

 made of the lung juice. Cultivations made of the lung 

 tissue, the liver, and the spleen, always yield a great 

 abundance of colonies. As the result of inoculations 

 made with the culture of the grouse into the sub- 

 cutaneous tissues of guinea-pigs, about 50 per cent of 

 the animals die during the third or fourth day ; the 

 others, though they survive, develop a firm tumour 

 at the seat of inoculation. But all the guinea-pigs 

 are distinctly ill 24 hours after inoculation ; they show 

 a slight soft swelling at the point of inoculation, 

 and are quiet and off their food ; some grow weaker 

 during the second and third day, cannot move, are 

 shaky when they attempt to move, and gradually 

 sink and die. At the post-mortem examination the 

 subcutaneous tissue at and about the seat of inocula- 

 tion, on the abdomen, and even on the chest, is 

 oedematous and shows haemorrhage. The blood of the 

 right heart is fluid, both lungs are much congested ; 



