Studies on Inheritance in Pigeons; IV. Checks and Bars and Other Modifications of Black
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 edition. Excerpt: ...are changed. For example, it was pointed out in section III that Cole (1914) considered all checks, (only checks were involved in the three illustrative matings used by him, no black blue-tails or sooties), as blacks and consequently he expected three blacks and checks to one barred. Since, however, the existence of the checking factor has been determined the former 3:1 ratio becomes a 15:1, as two factors instead of one are noVinvolved. If, on the other hand, the present interpretation is correct all blacks heterozygous for S when bred inter se should give a 3:1 ratio, considering black blue tailed birds and all individuals below as s_ The combined data of tables 4, 9 and 11 fit this ratio with the observed numbers 71:28 and the expected 74.25:24.75. The P.E. of the ratio is.12 and the SJj is 1.08. Similarly tableslO, 12A and 13A give numbers for a 1:1 ratio, the total observed being 43:55 and the expected 49:49. The P.E. in this case is.068 and the Dev. is 1.47. These results are in keeping with the FX" present hypothesis. Unless some stage shall be found that is dependent upon S_ the ratio between J3 and s. will continue to remain the same. If, however, more intermediates involving both S_ and s_ should later "be isolated the various ratio? existing between the present known factors will become altered. It seems, furthermore, highly pro"bable that more factors are concerned, since the series appears to grade from black through to a pure gray wing lacking any black except that confined to the tips of the primaries, secondaries and tertiaries. If six trades in this series have been shown to exist independently, there is no reason.why others could not also be split off, for students of drosophila have found...
- 189 x 246 x 1mm | 64g
- 13 Sep 2013
- United States
- black & white illustrations