l6o I'ori.TKV DISKASKS AND TllKlK IKKAT M K NT. 



DISKASKS (il- rilK ()\A1<N'. 



.Itropliy of the Oi-ar\. 

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

 that orij^an accompanied with a cessation of its physiological 

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

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

 the ovary may he distinguished. The different sorts are sepa- 

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

 result. l)Ut because of the different etiological factors concerned. 



1. Physiological atrophy. 

 a. Temporary. 



1). IVTinanent. 



2. Congenital atrophy ( Pseudo-hcrmaphroditismV 



3. "lUack 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 

 temporarw 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 hapi)ens that the ovary passes min an atrophied 

 condition, and remains permanently in that condition thereafter. 

 In such cases the l)ird 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 uf the latter 

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

 in their ])ullct years. 



It shoidd l)e noted that in what is here called permanent ]ihysi- 

 ology atrophy of the ovary there is ;/() 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 



