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Poultry Research. 



[May, 



of the comb, but he is anxious to learn anything concerning the 

 inheritance of factors that affect the number and size of the eggs, 

 as well as the fattening qualities of the bird. Egg-laying trials 

 serve an exceedingly useful purpose, but they do not necessarily 

 throw a searching light on the subtler aspects of heredity. It is 

 not difficult to understand that the trials can hardly be conducted 

 with that regard for scientific precision demanded by the student 

 of heredity, and that, therefore, more rigid control, and the 

 recognition of precise rules of experimentation, may be regarded 

 as necessary for the discovery of facts upon which laws may be 

 formulated. 



Pathology of Reproduction. — Reproduction, moreover, has its 

 pathology. Not by any means of trifling economic importance 

 are those obscure disturbances of the reproductive organs which, 

 though not generally recognised as actual diseases, are yet suffi- 

 cient to lead to faulty egg-production. These, too, require 

 investigation. 



Research in Poultry Diseases. — In the province of pathology 

 and bacteriology, it is impossible accurately to estimate the 

 benefits that would accrue to the poultry industry from dis- 

 coveries arising out of research. There can be no question that 

 the benefits would be many, and we may obtain some idea of 

 them by a review of any one of the recognised diseases, as well as 

 by a summary of the confessed gaps in current knowledge 

 respecting its etiology and control. For such a review and sum- 

 mary almost any disease would serve, but an instructive example 

 might be found in a disease of which few poultry-keepers have 

 the good fortune to be ignorant. I refer to that disease or group 

 of diseases known by a multiplicity of names — roup, diphtheria, 

 bird pox, &c. In the forefront of many questions stands that 

 of Cause. Is there one main factor? Or are there many? If it 

 should be determined that there is only one causal agent, then 

 how is it that such a gamut of manifestations can be induced? 

 When these and many other doubts of a like nature have been 

 cleared, there will arise an inquiry into the best and surest 

 method by which the disease or diseases may be combated and 

 controlled. 



Carriers of Disease. — There is also the matter of " carriers." 

 It is recognised that apparently healthy mammals may be 

 " carriers " of diseases, and in avian pathology it is also recog- 

 nised that an apparently healthy pullet may be a " carrier " 

 of the virus of bacillary white diarrhoea. It is probable that fowls 



