CHAPTER XVIII. 



Diseases of the Repkoductive Organs. 



The direct economic importance of poultry lies in the produc- 

 tion of two things, viz., meat and eggs. For the production of 

 the latter the poultryman is dependent upon the activity of the 

 reproductive system of the hen. Under natural conditions in 

 the wild state, the progenitors of the domestic fowl laid rela- 

 tively few eggs. Judging by other species of wild birds of the 

 present day, however, it is highly probable that the wild pro- 

 genitors of poultry possessed the potential ability to lay much 

 more than the usual number of eggs provided they were removed 

 from the nest as fast as laid. Under domestication this practice 

 of removing the eggs as fast as laid, together with the feeding 

 of rich foods, and still other factors, lays heavy demands upon 

 the reproductive system. It is not remarkable that an organ 

 system which under conditions of nature produced from 12 to 

 perhaps 30 units per annum, frequently breaks down under 

 the strain of producing from 100 to 250 per annum of the same 

 kind of units. It could only be expected that, as is actually the 

 case, the egg producing organs would be particularly liable to 

 disease. '; 



ANATOMY AND PHYSIOLOGY. 



In order that the discussion of the diseases of the reproductive 

 organs may be intelligible it is desirable to preface it with a brief 

 account of the anatomy and physiology of the organs of repro- 

 duction in the hen. Because of -the fact that the corresponding 

 organs in the male are less subject to disease, on the one hand, 

 and are perhaps better understood by the poultryman, because 

 of the prevalence of the practice of caponizing, on the other 

 hand, it will not be necessary to discuss the male in detail in 

 this connection. 



The organs concerned in egg production in the hen are shown 

 graphically in fig. 40. This picture and the accompanying ex- 



