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Show 128 MR. L. DONCASTER AND REV. G. H. RAYNOR ON [Feb. 20, T A B L E V±.-Plain sordiata X prunaria. No. of Exp. 04.20 34 28 $ PARENT. $ PARENT. ? pi. sord. ex 03.3 X S prun. ex 03.4 J> »> x ,, ,, $ prun. ex 03.4 X <Jpl. sord. ex 03.3 Total OFFSPRING. speck, sord. <?. speck, sord. $ . 8 5 1 3 5 3 14 11 T A B L E VII.-Speckled sordiata x plain sordiata. No. of Exp. 04.23 33 35 $ PARENT. £ PARENT. ? spec, ex 03.3 X <J plain ex 03.3 >> JJ X ,, ,, Total OFFSPRING. plain plain speck, speck. sord. £ . sord. ^ . sord. $. sord. ^ . 2 5 2 6 3 4 11 11 2 7 4 From these tables I think it is sufficiently clear that the banding of the sordiata is dominant over its absence in prunaria, but that the speckling of pruna,ria is at the same time dominant over the plain orange of the pure sordiata, giving a heterozygote which is both banded and speckled (PI. VIII. fig. 2). The plain sordiata, however, may have some specks along the wing-rays, so that an exact determination of the numbers of " plain " and " speckled " is not possible. The numbers of these two classes in the tables are therefore approximate. The numbers are not sufficiently large to show whether the different types occur in the proportions demanded by Mendel's Law, with the exception of those in Table III. Here there are 148 prunaria to 110 sordiata, where equality is expected; but the mortality is so great among the young larva?, and also during hibernation, that a very small differential mortality will account for this. The work was partly undertaken to find out whether there was any tendency for a correlation of either of the types with one or other of the sexes, but no evidence whatever of this has appeared. It is important to notice that no intermediates occurred; in fact the darkest prunaria bred were from two prunaria parents, and the lightest sordiata from sordiata parents. |