1911] Heredity in Adalia 293 



acters of the first generation it was not thought necessary to 

 draw this parent. 



Figure 2, Plate XX represents the annectans-humeralis hybrid 

 female and her progeny resulting from union with a melano- 

 pleura-annectans hybrid male, and also for the last few days of 

 the experiment, with a pure annectans male. The numbering 

 of the spots is after Weise taken from Johnson 1910. In this 

 case the progeny would contain four strains of annectans, one 

 from the mother, one from the melanopleura-annectans father, 

 and two strains from the annectans father, which, however, 

 could hardly have affected more than the last three batches of 

 eggs. This would be just the number of strains to be repre- 

 sented if two members of annectans were mated. The males in 

 this case were both lost and so can not be shown in the figure. 

 Of the batches after the annectans male was introduced, in the 

 elytra series, one beetle was in class (d), six in class (e), 

 three in class (f), and one in class (i). In the pronota 

 series four were in class (k) and seven in class (1). There was 

 considerably less variation among these than in the foregoing 

 batches, but whether it was due to the annectans male or to 

 environmental influences can not be ascertained with certainty; 

 but as these were reared later in the season than the foregoing 

 batches, during the latter part of August and the early part of 

 September, during which time an unusually cold wave occurred, 

 the only environmental influence would probably have been a 

 lower temperature. This factor, however, would, from the 

 experience of Tower* and Johnson, be expected to produce a 

 melanic effect, but here the difference was albinic rather than 

 melanic, so the case does not seem to be explained by the 

 environmental factor, and unless it was produced by some 

 unknown cause, seems most probably to have been due to 

 heredity factors introduced by the annectans male. 



It will be noted in this case, Figure 6, curve (a), Plate XXI, 

 and Figure 7, curves (a), and (b) Plate XXII, that all of the 

 beetles, of both melano pleura and annectans, which were reared 

 from this female were rather at the albinic end of the scale as to 

 both elytral and pronotal characters. In the elytra none 

 have more than two full confluences and the mother ranks at 



* Tower, William Lawrence, 1906. An Investigation of Evolution in Chrysom- 

 elid Beetles of the Genus Leptinotarsa. Carnegie Institution of Washington, 

 Pub. No. 48. 



