312 



MAINE AGRICULTURAL EXPERIMENT STATION. 



I9l6. 



JO 





/O 





■as ./s 



.65 .35 



.25 .35 .45 .55 .65 .Z5 

 POS/T/OA/ /A/ L/TT£T/? 



Fig. 54. Showing the number of dwarf eggs which occurred in each 

 tenth of a litter. Dash line = the mean frequency. 



data then indicate that a dwarf egg is equally likely to occur at 

 any time during a period of production. 



C. The Position in the Clutch. A fowl seldom lays on every 

 day during a litter. The actual time between successive egg^ 

 depends on the rate of fecundity of the individual at the time. 

 This rate differs greatly with the individual and with the 

 season of the year. Since fecundity finds its manifestation in 

 discrete units (eggs) the result of a very low rate is expressed' 

 by the production of an egg on a day preceded and followed 1 

 by one to several days on which no egg is produced. A com- 

 mon low fecundity rhythm results in the production of an egg 

 on every second day. More usually an egg is produced some- 

 what later on each of two or more successive days and then a 

 day follows on which no egg is produced. The next egg 13 

 produced early on the following day. The litter is thus broken 

 into a series of daily eggs, which we may call clutches, sepa- 

 rated by one or more days on which no egg is produced. The 

 size of a clutch varies from one egg to the extreme and unusual 

 cases where a whole litter (sometimes of more than forty eggs) 

 is laid in a continuous daily series. 



The general acceptance of the notion that a dwarf egg marks 

 the end of a period of production suggests an investigation 

 of the position of the dwarf egg within its clutch. In 197 of 



