1921.] 



Poultry Research. 



161 



may be ' ' carriers ' ' of other diseases, but investigation on scien- 

 tific lines can alone prove this. 



Poultry Research. — That pathological and bacteriological 

 research will always be fruitful, in varying measure, is beyond 

 question, and it cannot be doubted that any discovery in avian, 

 no less than in mammalian, pathology will inevitably show that 

 there is something further to seek. There is no finality in 

 pathological research any more than there is in any kind of 

 biological research. Those who are following modern thought in 

 Medicine know that recently a change has crept into the con- 

 ception of the causation of diseases due to bacteria. Time was 

 when it was considered sufficient to recognise two factors in 

 disease — the tissues of the animal attacked, and the attacking 

 micro-organism. Now, however, experiments have hinted at 

 the possibility of a third factor — or " third partner in disease," 

 as it has been called — acting on the animal tissues and breaking 

 down their defence, thus permitting the micro-organism to exert 

 its pathogenic power. When the precise nature of the " third 

 partner " has been disclosed, and the means of nullifying its 

 effects have been devised — thus putting a further restraint 

 upon the activity of the pathogenic organisms — research will 

 proceed to an inquiry into the still more efficient control of the 

 causes of disease. Whatever advance is made in pathological 

 knowledge in general, will be possible of application to the con- 

 trol of avian diseases. Clearly, then, facilities and opportunities 

 for the application of general knowledge to the special problerns 

 of poultry diseases cannot fail to lead to beneficial results. 



While poultry research has a wide field in the investigation of 

 diseases concerning which something, at least, is already known, 

 it has an even wider field in the discovery of the true cause of 

 many diseased conditions not yet clearly identified. Is it not 

 true that even the poultry-keeper of wide experience occasionally 

 encounters a condition that, in spite of his long acquaintance 

 with the frailties of domestic birds, he has not previously seen, 

 and to which he cannot give a name? The pathologist who has 

 made a special study of avian diseases is often in the same 

 position. 



Among the numerous investigations that are awaiting the 

 attention of research is that dealing with the action of drugs. 

 From the very limited observations made, it is evident that the 

 effects < f drugs on birds cannot be predicted with certainty. 

 This is riot surprising, for it is well known that different species 

 of mammals exhibit variation in their tolerance to toxic drags, 



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