CHAPTER VII. 

 DEFECTIVE CYCLES. 



The reproductive cycle consists of numerous activities which, when normally 

 related to each other in a definite temporal order, are nicely adapted to achieve 

 that essential result the production and rearing of young. While harmony and 

 adaptation are the rule, yet certain faults, defects, and abnormalities, serious and 

 trivial, frequently occur. In the normal series of events it is evident that these 

 activities must stand in some sort of a mutual relation of cause and effect. To 

 the analysis of this causal interdependence the normal series of events can furnish 

 but little help. The key to this analysis lies here as everywhere in experimental 

 control and alteration of the order of events. The defects and abnormalities 

 which are described in this chapter possess not only an interest per se, but they 

 may be regarded as isolated bits of nature's own experimentation which may 

 furnish some help towards the proper analysis of that complex organization of 

 activities constituting the reproductive cycle. For the most part, these accounts 

 consist of excerpts and digests from the various records which present the essential 

 facts pertinent to our purpose. 



BRONZE-WING. 



FIRST CYCLE. 



The eggs were laid on December 16 and 18, 1905. The incubation record was 

 normal up to December 17. The eggs were hatched on January 3 and 4. During 

 the last week of the incubation period the male participated fairly well in his 

 incubation duties, but deviated from normal behavior by attempting to entice 

 his mate to desert the eggs and start a new cycle. After hatching, the male 

 refused to cover or feed the young properly and consequently both died within a 

 few days. A new cycle was started immediately afterwards. 



The male thus discontinued his cycle of activities, without any apparent 

 external cause, 15 days before its natural end. The female continued her cycle 

 for 11 days, or until the death of the second young on January 7, in spite of a number 

 of disturbing factors. These were, (a) the necessity of doing extra duty in the 

 care of the young, (6) the continual solicitations of the male, and (c) the death of one 

 young. With the death of the second young, the normal sequence of activities 

 was interrupted 4 days before its normal completion and a new cycle was started. 



The above facts are verified, and the necessary details supplied, by the following 

 excerpts from the daily incubation records: 



Dec. 27. At 3 h 45 m p. m. the male calls again five times and the female answers once. 

 The male this time does not attend to the call of his mate, but walks back and forth on 

 the side of the cage. His many calls evidently indicate that he has a sexual inclination. 

 At 4 h 44 m p. m. the male walks nearer to the female, getting onto the edge of the nest, but 

 she sticks to the nest and gives a low call as much as to say: "I must be left alone." At 

 5 h 46 m p. m. 1 the male is again on the edge of the nest and the female protests by two more 



1 This is the normal time for the male to be on the perch for the night. EDITOB. 



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