POULTRY DISEASES AND T 11 K 1 K TRKATMENT. t6i 



internal secretion which in some way controls the secondary sex- 

 ual characters remains unchanged. 



As congenital atrophy of the oivry are to be classed cases of 

 pseiulo-hermaphroditism in fowls. In such cases a true, func- 

 tioning ovary never develops. There may be a body which in 

 gross features resembles an ovary, but it is inactive and does not 

 take even the first steps in oogenesis (egg formation). 



There may or may not be a testis like body present in these 

 cases. Not only is the egg producing activity absent in such 

 cases, but also in many of them at least, the internal secretion 

 normally produced by the ovary is lacking also. The bird then 

 takes on some or all of the secondary sexual characters of the 

 male. The appearance of such a bird is shown in fig. 41. 



Fig. 41. Showing a case of incomplete hermaphroditism. In front of 

 the line a-b the bird has the characters of the male, behind it the 

 characters of the female. The ovary was not functional in this bird. 

 (Original). 



As "black atrophy" of the ovary is here designated the 

 peculiar disease of the ovary first observed more than a cen- 

 tury ago in England as occurring in pheasants. The striking 

 feature of the disease is that under its influence the bird assumes 

 the plumage appropriate to the male. The change in the ovary 

 and oviduct induced Iiy the disease appears to be an atrophy ac- 

 companied by a blackening which is probably a true melanosis. 

 The following account of an outbreak of this disease about 50 



II 



