199 



discoloration may vary, according to the amount of 

 this effused and broken down blood, from the slightest 

 tinge to a colour almost black. 



In epidemics of acute septicaemia (septic fever) it 

 is no uncommon thing to find the more weakly birds 

 dying in this earlier stage of the disease. Those 

 adults which have just been enfeebled by breeding or 

 some special malenvironment, and those young ones, 

 which, though perhaps naturally strong in themselves, 

 have been both invigorating the germs and overtaxing 

 their own organs by a course of egg food, are particu- 

 larly apt to die at this point — a point where the 

 amateur pathologist, or for that matter any one who 

 depends on naked eye appearances alone, is almost 

 sure to fall into error. At best he can only guess at 

 the cause of the condition, because all that such an 

 observer will see is just the enteritis and nothing else, 

 whereas when the enteritis is septic in origin the 

 blood of the abdominal viscera will be found under 

 the microscope to contain great numbers of the septic 

 organisms. The white corpuscles of the blood will 

 also be seen in greater proportion than in health, 

 many of them presenting numerous dark spots in 

 their substance, and the nuclei of the red corpuscles 

 may often be found to be in different stages of break- 

 ing up. 



Should the biid survive this stage we shall find 

 the liver and spleen engorged with blood and much 

 enlarged, particularly the latter. This organ, which 

 in its normal condition is about i inch in length by 

 i-i6tli in diameter, i.e. in birds the size of a Canar}^ 

 may frequently be enlarged to as much as f inch or 

 even more, with a proportionate increase in girth. 

 Microscopical films prepared from smears of the cut 

 surface of these organs will reveal great numbers of 

 the bacilli. In the spleen will be found by far the 

 greater number, owing to its peculiar structure. In 



