The Process of Heredity ^^J 



tion. Other series were conducted solely for the purpose of fur- 

 nishing quantities of young fish for rearing. Still others were 

 followed for a while and then abandoned for lack of time to record 

 data, since it seems impossible to follow carefully more than about 

 three series at one time. Still other experiments gave results out 

 of harmony with the general trend of data. In fairness such 

 series should at least be mentioned, although it seems quite cer- 

 tain that the contradictory results were the outcome of poor method. 

 To distinguish these series from the more complete ones detailed 

 above, the various series will be designated by letter instead of 

 by number. 



3 Fragmentary Data 



Series A, June 20., igo6. Conditions of experiment not recorded. 

 Like Series i except that at i8 hours the H hybrids were noted 

 and drawn as being slightly more advanced than H pures. At 

 48 hours, however, the relative degrees of advancement shown in 

 Series i had been attained. There seems to have been a retard- 

 ing effect due to foreign spermatozoa, the same in kind but differing 

 markedly in degree from that seen in other series. No further 

 observations. 



Series B, June 28, igo6. This was one of several series that 

 served to show the importance of using freshly taken fish. In this 

 case the fish used had been in aquaria for at least ten days and 

 had not been regularly fed. Only one observation was made — 

 at 24 hours — when the following data were obtained: About 50 

 per cent of// pures developing, the blastodiscs very small. Only 

 10 per cent of H hybrids developing, but these with blastodiscs 

 more advanced than the H pures. About 50 per cent of M hybrids 

 developing. Only about 5 per cent of M pures developing nor- 

 mally. The great majority of the blastodiscs were irregular, 

 cleft or ruptured. None of this strain developed to an advanced 

 condition. A few M hybrids reached a condition about like {rnS). 



Series C, July 8, igo6. An incomplete series, not especially 

 contradictory. At 24 hours there was a much more marked 

 difference between H pure and H hybrid strains than shown in 

 Series i. The blastodisc of the H hybrids was about in the con- 



