1022 



Journal of Agricultural Research 



Vol. VI, No. 25 



occur unless the ovary was actively producing yolks. In none of the 

 above-mentioned cases was it impossible that a yolk had entered the duct 

 and started the formation of the egg. 



We have considered 5 of the 1 1 cases of dwarf-egg producers which were 

 apparently permanently abnormal. Autopsies were not performed on 

 the six other cases. The egg records for five of them (No. 6 to 10) resem- 

 bled the egg records of the birds just discussed. No normal eggs were 

 produced after the dwarf egg or eggs ; also the birds made nesting records 

 similar to egg records, indicating that the ovaries passed through normal 

 reproductive cycles. The relation of the occurrence of dwarf eggs to 

 normal eggs or nesting records was of a nature to show that they were 

 produced only when the ovary was maturing yolks. Several of the dwarf 

 eggs contained free yolk. 



The record of the other bird (case 11) is worthy of special mention. 

 This bird laid 1 7 dwarf eggs. These eggs were also produced when there 

 was evidence that the ovary was in functional condition. The unique- 

 ness of the case lies, first, in the unusual number of dwarf eggs, and 

 second, in the fact that, although the number of dwarf eggs and nesting 

 records and the proportion of these to normal eggs increased, some nor- 

 mal eggs were produced as long as there was any evidence that the bird's 

 ovary was in laying condition. The egg record of this bird is given in 

 Table XXIX. 



Table XXIX. — Egg record of case a 



a " 1 " denotes a normal egg, " i — " a dwarf egg, " n " a visit to a trap but no egg, and "s" date sold alive. 



A record was made of the contents of 16 of these dwarf eggs. Not one 

 of these contained yolk, but all of them contained varying amounts of 

 chalaza-like fibers, some resembling normal chalazse. Thirteen con- 

 tained no visible nuclei except the mass of coagulation fibers. One egg 

 (laid on August 26) also contained a small lump of hardened albumen. 

 The one laid on June 26 contained, beside the mass of chalazal fibers, a 



