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RAYMOND PEARL 



diately antecedent laying is not a requisite for the manifestation 

 of the broody instinct. 



Similar evidence is afforded by the case of bird No. 130, 

 whose record is given in Fig. 10. This bird became broody 

 on March 16. The records show only one egg before this time 

 to her credit. Whether or not this egg record is an error it is 

 impossible to say. It make no essential difference in the inter- 

 pretation of the case. Perhaps the most striking feature of this 

 case is the fact that this bird went broody for a second time on 

 April 14, there having been no intervening egg production 

 between the broodiness of March 16 and that of April 14. On 

 May 2 and on May 10 the bird laid an egg. This record essen- 

 tially confirms the results shown in the case of bird No. 699. 



Figure 10. Showing the record of bird No. 130. 



The record of bird No. 320 is interesting in this same con- 

 nection. This record is shown in Fig. 11. 



Here there are four distinct and separate manifestations of the 

 brooding instinct between March 25 and July 1. The first 

 period of broodiness began on March 25. Before this time the 

 bird had laid 12 eggs, 11 of them in January and one in March. 

 This egg in March was laid on the 8th and it was 17 days after 

 this before broodiness appeared. It would be extremely difficult 

 to establish any connection between the antecedent laying and 

 the broodiness in this case. On April 19 the bird laid again, 

 this being the first egg since the one of March 8. On April 21 

 she became broody again, but this was only a mild attack, for 

 she showed visible manifestations on the 24th and laid on the 

 26th, only to become again broody on the 30th of April. She 

 was released on May 4 and laid May 12 and May 16. The 

 latter of these was her last egg before July 1. Twenty-nine 



