sept, is, 1916 Dwarf Eggs 1025 



At the time of autopsy cases 19 and 20 showed a pathological con- 

 dition of the oviduct which prevented the entrance of a normal yolk into 

 the duct. The fact that these birds continued to be good layers for 

 nine and five months, respectively, after the dwarf egg had been pro- 

 duced and then, by the cessation of normal-egg production and the occur- 

 rence of nesting records, showed a disturbance in their normal-egg pro- 

 duction makes it seem probable that the pathological condition found at 

 autopsy did not originate until some time after the dwarf egg had been 

 produced. At least it is not safe to assert that a pathological condition 

 of the duct existed at that time. 



Of the seven cases of birds which either had a dwarf egg in the oviduct 

 or body cavity at autopsy or had laid such an egg a few hours before 

 death all had normal sex organs in fully functional condition. Each of 

 these cases seems worthy of brief description. Case 21 was a late- 

 hatched pullet which did not show any l reproductive activity until 

 February. She then made a series of four nesting records and produced 

 the dwarf egg as her first egg. The egg contained two small lumps of a 

 dark, hard secretion and stringy albumen threads which looked like 

 untwisted chalazse. There was no yolk in this egg. The bird was killed 

 a few hours after the egg was laid. She was in every way a normal 

 healthy bird. The ovary contained a normal series of six enlarging 

 yolks and four large and three small follicles. In the body cavity there 

 were a few centimeters of a serous fluid containing yolk. In this fluid 

 were found strings of tissue which may have been vitelline membrane. 

 This pullet was then in full-laying condition; but for some reason not 

 associated with an abnormality of the oviduct the yolks did not enter the 

 duct, but were ovulated into the body cavity and absorbed. The origin 

 of the stimulus which initiated the formation of the dwarf egg is not 

 clear. While it is possible that all or part of a yolk entered the duct and 

 was later extruded, there is no evidence for or against this view. 



Case 22 was a normal pullet which had produced 48 normal eggs. She 

 produced five normal eggs on successive days and on the sixth day pro- 

 duced the dwarf egg. The egg contained a lump or drop of yolk the 

 size of a bean. The bird was killed a few hours after the egg was laid. 

 The ovary contained a normal series of five enlarging yolks and four 

 large and four small empty follicles. These follicles were all apparently 

 normal and empty of yolk membranes. The body cavity contained a 

 fluid which was partly yolk. In this case there can be no doubt that a 

 normal yolk was ruptured either during ovulation or afterwards in the 

 duct or body cavity and that a part entered or remained in the duct, 

 forming the nucleus for the dwarf egg, while the rest was being absorbed 

 by the visceral peritoneum. 



1 A lone nesting record occurred in December, but the bird may have accidentally gone into a nest. 



