THE BROODING INSTINCT IN THE DOMESTIC FOWL 271 



3. A raising of the feathers over the whole body, giving the 

 bird a ruffled and very much enlarged appearance. 



4. A marked pugnacity of behavior when anything approaches 

 the sitting bird. 



This brief statement gives an idea of the criteria of broodiness 

 used in actual practice by the poultryman. When a bird ex- 

 hibited these symptoms in a characteristic manner, she was 

 confined and a ' B ' entered on the record. The records of 

 onset of broodiness discussed in this paper can be unreservedly 

 accepted as accurate and complete. 



Turning to the " O " or release records, the case is somewhat 

 different. A bird is in practice released from the detention 

 coop when she no longer exhibits the symptoms of broodiness 

 but instead appears normal in her behavior. Now since, as a 

 matter of fact, there is not a sudden disappearance of the mani- 

 festation of broodiness following confinement, but instead a 

 gradual subsidence of the symptoms, it must be clear that the 

 time when a bird shall be released is an extremely difficult matter 

 to decide. And further, records of the dates of release do not 

 possess anything like so precise a metric significance as do dates 

 of incarceration, so far as the manifestations of the instinct of 

 brooding are concerned. The observer will frequently make the 

 mistake of releasing a bird too soon and there will be an immediate 

 recrudescence of the broodiness under the conditions of freedom, 

 necessitating a second confinement. Or again, there is reason to 

 suppose that sometimes the birds are kept in confinement too 

 long. Evidence of this is given in cases where the bird lays on 

 the same day that she is released. All that can be said regarding 

 the release records is that every care was taken to make them as 

 accurate and significant (i.e., in relation to the cessation of the 

 manifestation of broodiness) as possible. From the nature of 

 the case, however, they are not and cannot be precise records. 

 This means that a great deal of caution must be exercised in 

 drawing conclusions from them, and each individual case must 

 be considered critically. 



With these statements as to the character of the data in hand, 

 attention may be turned to some actual records selected to 

 bring out the following points : 



1. Broodiness as a cyclical instinct. 



