292 POULTRY CULTURE 



has long been observed. Shifting from place to place and chang- 

 ing diet are common methods of checking egg production in pullets 

 which it is desired to keep from laying in order that they may be 

 in better condition for exhibition or for breeding at a later season. 

 Recent studies of the reproductive organs of hens at the Maine 

 Agricultural Experiment Station show that the development of these 

 organs should be regarded as continuous from the earliest stages of 

 the growth of the bird, and not, as has been the common view, as a 

 part of the general development of the bird until the rest of the 

 organism is complete, and then a special growth of the organs of 

 reproduction. It has often been observed that pullets just beginning 

 or about to begin to lay were more sensitive to disturbances and 

 changes than those that had been laying for some time. From this 

 it has been generally assumed that at the beginning of functional 

 activity the reproductive system of the bird was especially sensi- 

 tive, and that prior to that time the reproductive organs were 

 not at all sensitive. On this theory the pullets are often handled 

 less carefully in early life than as they approach the age when they 

 should begin to produce eggs. This subject cannot be discussed 

 exhaustively here. So little has it been investigated that knowledge 

 of it is at almost every point deficient. It can only be treated in 

 its most obvious phases and in general terms. Although much 

 relating to it is in doubt, enough is known to show that every con- 

 dition and circumstance unfavorable to the growth of the body may 

 still more unfavorably affect the development of the organs of repro- 

 duction. Every one of the numerous factors unfavorably affecting 

 growth must therefore be regarded as likely to affect the reproductive 

 system more seriously, and to delay its functional activity far beyond 

 the time when growth of the body is complete. This theory explains 

 many cases of retarded egg production which otherwise seem inex- 

 plicable. Not all cases of retarded egg production are due to such 

 remote or indirect causes. In many cases direct causes are found 

 sufficient to prevent egg production. But when no direct cause can 

 be found, it may reasonably be presumed that there was a remote 

 cause (or causes) sufficient to produce the results ; and when it is 

 known, as it often is, that growth was retarded or interrupted, the 

 cause of that interruption may be considered a sufficient cause for 

 failure of egg production to begin promptly when growth ceased. 



