DWARF EGGS OF DOMESTIC FOWL. 309 



more than three dwarf eggs, two that produced three, one that 

 produced two, and four that produced only one dwarf egg. 

 The production of a succession of dwarf eggs or of a long 

 series of nesting records with one or two dwarf eggs should 

 lead one to suspect a serious disturbance of the oviduct. 



We will first consider dwarf egg production which is not 

 associated with a morphological abnormality of the sex organs. 



VIII. The Relation of Dwarf Egg Production by Normal 

 Birds to the Age of the Bird and to the Position of 

 the Egg in the Litter and Clutch. 



A. Age. The age of the bird at the time the dwarf egg 

 was laid could be determined in 202 cases where a dwarf egg 

 was laid by a normal bird. The age frequency distribution is 

 given below. 



Age in Days. Dwarf Egg Frequency. 



1 50-209 11 



210-269 14 



270-329 22 



330-389 65 



390-449 5 2 



450-509 19 



510-569 * 4 



570-629 o 



630-689 3 



690-749 6 



750-809 2 



810-869 2 



870-929 o 



930-989 o 



990-1049 1 



1050-1 109 I 



202 



It has already been noted that a large part of the birds are 

 disposed of at the end of their first laying year. That is when 

 they are 15 to 17 months of age. There were, therefore, many 

 more chances for a bird to lay a dwarf egg during her first 

 year than later in life. From data in hand it is not possible to 



