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Show 854 MR. W. BATESON ON THE [Dec. 3, two black spots (see figs. 19-24), while in the spotted forms the thorax is generally black with some lighter colour at the periphery and not rarely in the middle line. Considering the ground-colour of the elytra there are thus two chief kinds, red and greenish grey. The majority can at once be referred to one or other of these two. Nevertheless there are intermediate colours forming an unbroken series or transition from the one to the other. Such a series is represented in figs. 1-6. Starting from the bright red kind (fig. 1) and passing through a duller red (fig. 2) a neutral buff (fig. 3) is reached. This buff is almost exactly intermediate between the red group and the greenish grey. The next stages in the transition are yellow (fig. 4), yellowish green, and greenish grey (fig. 6). Taking spotted males alone the bright reds are by far the commonest, the duller reds are the next commonest, the buff are very rare, while yellows and greenish together make up a fair group. As to the relative frequency of these yellows and greens, the data are unreliable. The total number belonging to these classes was small, and it is not possible to sort them among themselves with any strictness. I am satisfied that the yellows are more common than the buffs, and the spotted greenish greys are probably less common than the yellows ; but of this I a m not sure. In the Table given at the end I have united them. Of striped males almost all are greenish grey. Eeds and yellows occur, but are exceedingly rare. The whole number of striped specimens with a ground-colour other than greenish grey is so small that it is not possible to judge the frequency of the respective colours. I attempted for some time to distinguish different shades of the greens according to the degree of yellow. But while certain of the striped kinds are obviously yellow and others are obviously yellowish green, it was not found possible to sort consistently the yellowish greens from the greens with less yellow, so this attempt was abandoned. With a view to determining the nature of the colouring-matters, an examination of some specimens was very kindly made by Dr. H . C. Sorby. The material sent to him consisted of a few of the reds and a few of the greenish form separately killed and preserved in alcohol. Dr. Sorby informs m e that the red pigment is slowly dissolved out by alcohol and carbon bisulphide, and when in solution in the latter is of exactly the same character as the similar pigment of the common Lady-bird (C. bipunctata). After long action to dissolve out all the pigment of the elytra, the red form is left of a yellow colour, exactly like that which is assumed also by the greenish kind. Dr. Sorby therefore conjectures that the reds differ from the others mainly on account of the development of the red pigment which is not found in the others. It is therefore possible that the ground-colours intermediate between the red and the greenish may be due in some measure to a difference in the amount of red pigment; but it seems likely that in the |