90 



than did even the physician of less than half a centun' 

 past. To take one example for instance — the recondite 

 rubbish taught at that time about "scrofula" and 

 "consumption" and their heredit\^ resolves itself 

 to-day into the tubercle bacillus with its own special 

 life history, and its capacity for attaching itself to 

 individuals even irrespectively of their grandmothers. 



Hence it comes about that by the light of latter- 

 day knowledge and methods it may be laid down as 

 an axiom that in eight out of ever}^ ten cases no 

 one, whether he be a trained medical or veterinary 

 practitioner, or even a highly untrained laA^man, can do 

 much more than guess at the cause of a bird's death 

 unless he calls to his aid a modern microscope with 

 its man}' accessories, and is furthermore able to read 

 correct!}' the story it unfolds. 



One of the commonest ultimate causes of the 

 deaths of such birds as experience the roses and 

 thorns of what we may call civilization — alias captivity 

 — is that ubiquitous microbe the septic bacillus. The 

 spores of this active and indeed useful organism, (for 

 it plays the chief part in ridding us of all animal and 

 vegetable bodies that are finished and done with as 

 integral factors in the world's economy), are every- 

 where present, existing even in the air in countless 

 myriads. It can therefore be easily understood with what 

 facility a bird's system may be invaded by this humble 

 yet powerful agent ; although it must be equally 

 remembered that only in a minority of the instances 

 of invasion does it cause the death of its host. This 

 latter statement must not be taken as a contradiction 

 of the former one ascribing a large proportion of the 

 deaths to this micro-organism. It is by no means 

 such, because even those birds that at last die of 

 Septicoemia in some form or other have often in the 

 past played the host to its bacillus, but have for the 



