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The droppings of an infected bird are teeming with 

 untold myriads of the pathogenic bacteria ; the beech 

 mast and any other foods lying on the ground become 

 contaminated by these droppings, as does also the 

 stagnant water in the ditch or furrow nearest to the 

 feeding grounds to which these birds resort after the 

 manner of all pigeons directly after filling their crops. 

 And so to the medical biologist it is no secret how a 

 crowded community of highly susceptible wild birds 

 becomes almost exterminated from time to time — to 

 their ultimate preservation as a species. 



That this form of fatal disease is due— as is 

 surmised by an anonymous commentator of the 

 gamekeeper's — to chronic irritation of the gullet by 

 the fine hairs on the beech mast, is untenable. For a 

 bird to die while yet one of " the fattest I have ever 

 seen," as the gamekeeper says, shows that its illness 

 has been of very short duration, and its throat deposit 

 of correspondingl}^ rapid formation. Putting, how- 

 ever, these acute cases on one side, and considering 

 only those which might conceivably be due to chronic 

 irritation by beech mast or any other food, we shall see 

 that, for this to be so, the disease would not be 

 epidemic but endemic in its character, i.e. there 

 would always be a more or less steady average of cases 

 occurring every year. And it will be equally plain 

 that in this case the birds themselves would long ago 

 have worked out their own salvation from the danger 

 by the natural processes of evolution, i.e. by survival 

 of the fittest, (seeing that beech mast has formed a part 

 of their food for countless ages), just as the domestic 

 pigeon has nearly arrived, by at the least 5,000 years 

 of close contact with the septic bacillus, at the goal 



