ioo2 Journal of Agricultural Research vol. vi.no. 25 



mum dwarf-egg production the proportion of dwarf to normal eggs was 

 8.6 dwarf eggs in 10,000, or 1 dwarf egg in 1,158 eggs. Warner and 

 Kirkpatrick (26) show that during two laying contests at Storrs, Conn., 

 I 99> 1 37 e SS s were produced, of which 103 weighed less than 0.09 pound 

 (40.82 gm.). From these figures we see that they obtained 5.2 dwarf 

 eggs per 10,000, or 1 dwarf in 1,933 e gg s - 



The nine flocks which laid the dwarf eggs considered in this investiga- 

 tion contained approximately 4,800 different individual birds. Not all of 

 these birds had an equal opportunity to lay a dwarf egg, for while a 

 large majority of them were kept until, and only until, the end of their 

 pullet year, a number died at varying ages and a number were kept for 

 more than one year. Also the records for 1907-8 and 191 5-1 6 are 

 incomplete. We may, however, arrive at an approximate estimate 

 of the proportion of birds which lay one or more eggs by neglecting these 

 discrepancies and considering that each of the 4,800 individuals had an 

 equal opportunity to produce dwarf eggs. 



The 251 dwarf eggs of known origin were produced by 200 different 

 individuals. There were 47 eggs laid by birds whose number was not 

 known. Most of these were floor eggs. In a very few cases the poultry- 

 man neglected to record the number of the bird on the egg at collection 

 time, and in a very few others the trap-nest record of the bird laying the 

 dwarf egg was lost through some other slip. Since most of the dwarf 

 eggs of known origin were produced each by a different individual, we 

 shall arrive at the fairest estimation of the number of birds which pro- 

 duce dwarf eggs by considering that each of these 47 was laid by a 

 different individual, and by one which had not produced one of the' 

 dwarf eggs of known origin — that is, we may consider that the 298 eggs 

 collected were produced by 247 individuals. From the above consider- 

 ations it appears that during the last eight years at the plant of the 

 Maine Station 247 out of 4,800 birds, or 5.15 per cent, produced at least 

 one dwarf egg. 



By means of the data given by Warner and Kirkpatrick (26) we may 

 also approximate the relative number of dwarf -egg producers among the 

 birds in the third and fourth laying contest at Storrs, Conn. These 

 birds also did not all have an equal chance, since the data were worked 

 up after 7 of the 12 months of the fourth contest. During these con- 

 tests 85 out of 1,820 birds, or 4.67 per cent, laid one or more dwarf eggs. 

 If the data had been digested after the fourth contest had been completed, 

 k is quite probable that a few more birds would have laid dwarf eggs — 

 that is, the percentage given may be too low. 



The close agreement of the two approximations indicates that about 

 5 per cent of the birds in an average flock will produce at least one 

 dwarf egg. 



