l6o POULTRY DISEASES AND THEIR TREATMENT. 



DISEASES OE THE OVARY. 



Atrophy of the Ovary. 

 By "atrophy" of the ovary is meant a diminution in size of 

 that organ accompanied with a cessation of its physiological 

 activity. It may shrink to the size and appearance which it 

 has in a very young bird. The following sorts of atrophy of 

 the ovary may be distinguished. The dififerent sorts are sepa- 

 rated from each other, not because of any difference in the end 

 result, but because of the different etiological factors concerned. 



1. Physiological atrophy. 



a. Temporary. 



b. Permanent. 



2. Congenital atrophy (Pseudo-hermaphroditism). 



3. "Black atrophy." 



A physiological diminution in size or partial atrophy of the 

 ovary occurs normally in fowls when after a period of laying 

 they go into a more or less prolonged resting period. The con- 

 dition of the ovary is usually (in fowls under 2 years old) only 

 temporary. The organ resumes its normal size and activity af- 

 ter a time. In old birds (3 to 6 or more years of age) it not 

 infrequently happens that the ovary passes into an atrophied 

 condition, and remains permanently in that condition thereafter. 

 In such cases the bird as a whole, and the ovary in particular, 

 may be perfectly healthy, showing no sign of disease. Cases 

 of permanent physiological atrophy of the ovary have been ob- 

 served at this Station as follows : 



One case in a White Crested Black Polish. 



One case in a Cornish Indian Game. 



Several cases in Barred Plymouth Rocks. All of the latter 

 were birds of very high fecundity (200 or more eggs per annum) 

 in their pullet years. 



It should be noted that in what is here called permanent physi- 

 ology atrophy of the ovary there is no associated change of the 

 secondary sexual characters. That is, the hen does not assume 

 cock plumage, spurs, enlarged comb and wattles, nor any other 

 of the secondary sexual characters normal to the male. This 

 indicates that in permanent physiological atrophy (just as is 

 known to be the case in temporary) the only function of the 

 ovary which is disturbed is that which is involved in egg for- 

 mation. The activity of the organ in regard to producing an 



