sport in Melasojna and its Behavior in Heredity 223 



There occurred, therefore, in the breeding room, a total of 20 

 AB, or sport individuals in a total of 11,369 individuals reared 

 during the breeding season, most of these coming from the imme- 

 diate collection of March 4. 



Inspection of the table shows that in the first generation, 168 

 matings were made, one brood only being reared from each pair. 

 Parentage was represented by both SxS and BxB matings. 

 The sport AB was found in the progeny of each series, ten in the 

 former, six in the latter. In other generations matings were made 

 in the S line only. In the second and fourth generations, single 

 broods only were reared from each pair, as in the first generation, 



TABLE I 



while in the third generation, an average of five or six broods were 

 reared from each pair (a minimum of two, a maximum of fifteen 

 broods). With three exceptions, not more than one AB individual 

 occurred in any one brood. In the first exception two individ- 

 uals (a male and a female), occurred in a single brood, in the 

 second exception five males occurred similarly, and in the third 

 exception two males. We find, therefore, in a total of 264 matings, 

 fourteen only producing sports. 



That the occurrence of the sport was normal, that is, was not 

 due to laboratory conditions, is evidenced by the fact that but com- 

 paratively few sports occurred (20 out of a total of 11,369 indi- 

 viduals.) Since all broods in the breeding room are under prac- 

 tically the same conditions, had an extrinsic influence been at work 



