C. B. TICEHURST: WOOD-PIGEON DIPHTHERIA. 73 



on the transmission of the disease. It can easily be 

 understood that transmission of a disease from member 

 to member in a vast horde, as in any crowded community, 

 can take place in a number of different ways. For 

 example, the exudation from a diseased bird's throat 

 may easily be " coughed " out (and, as breathing gets 

 more difficult, it is natural that it should be), and may 

 fall on to the plumage of a neighbouring bird which, in 

 turn, preens itself and takes up, of course, the bacilli. 



Another way, which I suggested in British Birds, 

 was that a diseased Pigeon after eating an acorn re- 

 gurgitated it, and this, being picked up by another Pigeon, 

 transmitted the bacilli of the disease. This suggestion 

 seems to have been quite misunderstood by some people, 

 for one writer in the " Field " shortly afterwards wrote 

 to say, that " except at the time they are feeding their 

 young. Pigeons do not regurgitate . . . and there 

 is no need to assume regurgitation, or to attribute to them 

 a habit which has not been observed " — which is absurd, 

 since if there is any obstruction in the gullet, solid food 

 will be regurgitated immediately that obstruction is 

 reached. 



Moreover, I have Mr. A. H. Patterson's evidence that 

 he had a Pigeon sent him by a friend who had shot it, 

 and that on the ground where the bird was sitting there 

 lay an acorn which it had evidently tried to swallow and 

 had regurgitated. 



Both young and old birds are affected, though the 

 occurrence of the disease in nestlings requires con- 

 firmation. 



IV. — Duration and Course of the Disease. — No 

 definite observations were made on this subject, though 

 it was inferred that from the condition of the birds 

 that the malady sometimes ran a quick course and 

 sometimes a lingering one. 



Through the kindness of Dr. Eyre and Mr. Deeming, 

 bacteriologists of Guy's Hospital, I was enabled to have 

 two Pigeons inoculated, and so obtain direct evidence of 



