C. B. TICEHITRST: WOOD-PIGEON DIPHTHERIA. 75 



agreed that the disease was prevalent during beech-mast 

 or acorn years. This difference of opinion is strong 

 evidence that the disease is not directly due to the kind 

 of food supply, but due to massing. 



In any crowded community the incidence of a contagious 

 disease is always high, and where in a less crowded one 

 a disease may be endemic, in a greatly crowded one it 

 will become epidemic. This rule applies in no less degree 

 to Wood-Pigeons, and it is the abundant food supply 

 which accounts for the massing, and the massing which 

 favours the spread of the disease. 



From the returns it would appear that where there was 

 any disease there was, in most cases, a plentiful supply 

 of either acorns or beech-masts, and in a few cases a 

 plentiful supply of either corn or green crops. 



VI. — Transmission to other Animals. — That this 

 particular disease is transmissible to other animals seems 

 certain, for Loffler, in his orginal researches on this 

 micro-organism inoculated, with mild results, fowls and 

 rabbits ; guinea-pigs and rats suffered more severely ; 

 while Wood-Pigeons and Sparrows succumbed. 



From observations sent in there is little to record. 

 Two observers noted the disease in Stock-Doves, one in a 

 Tawny Owl, and one or two affirm that they have seen it 

 in Pheasants and Partridges. In no case, however, 

 were any of these birds sent in for examination bac- 

 teriologically, and therefore there must always be some 

 doubt as to whether the disease was the same as that 

 under consideration. On the other hand, I have made 

 several enquiries as regards Pheasants and Partridges 

 being affected in quarters where it might be expected, 

 but have always received a negative answer, and on one 

 estate where about 4000 Wood-Pigeons were destroyed 

 last winter, and where 3000 Pheasants are shot every year, 

 no case of " diphtheria " in Pheasants had ever been 

 known. 



The only other evidence I have on this matter is of a 

 negative character, namely, that on this same estate 



