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856 MR. W. BATESON ON THE [Dec. 3, There is some suggestion that the frequency of the different variations may be in part dependent on locality. The great mass of m y specimens were collected on the hills that extend behind the towrn of Granada, separating the two valleys of the Genii and the Darro. In the first year I made a separate collection also from the Spartium growing near the bottom of the Darro valley. I noticed at once that the proportion of tbe striped forms with greyish-green ground-colour was much larger than it had been in the case of the hill-locality. Unfortunately I was not at that time expert in sorting the sexes, and this Darro sample was eventually mixed with the rest that I brought, living, to England. The colours were recorded, but without reference to sex. The second year, however, I made another attempt to get statistics of the Darro population, and give the result in Table II. The total numbers are unfortunately small, as the available area on which the Spartium grows is not extensive; but the quantity is sufficient to show that the proportions are markedly different from those of the hill-sides, for while on the hill-sides 19 per cent. of males are of the striped greenish grey, in the Darro valley about 37*7 per cent, are of that colour. I am disposed to think this difference in proportion is a perfectly genuine phenomenon and not merely an accident of collection, but I can suggest no cause for it. The difference in altitude is very slight, averaging, perhaps, 300 feet. No doubt the Darro bushes are rather larger and better watered, but many of the bushes on the hills are of the same character and I did not find a high proportion of greens on them. The Darro valley is no doubt less exposed and rather hotter than the hill-sides, but it would not be easy to point to a specific difference. A peasant employed as a " Guardia Municipal," with w h o m I made acquaintance, collected for m e a considerable sample of some hundreds from Pinos, higher up the Genii valley. The proportions agreed fairly with m y Granada sample; but as I knew nothing of the way in which they had been collected, the numbers are not worth giving. O n the 20th of March, 1895, during an interval between trains at Castillejo 1, a place not far from Toledo, in a hasty sweeping I got 75 specimens, only one being a female. Of these none are of the striped greenish-grey form. The number is of course too small to justify a conclusion ; but the result is remarkable, for according to the Granada experience there should have been about 14 such specimens. It is possible that in this more northern locality the proportions may be different. The scarcity of females is also to be noted and may perhaps be due to comparative backwardness of the season. It seems that at Granada at all events tbe beetles are to be found for a considerable part of the year, for Mr. Nicholson has kindly sent m e a small gathering made in the month of June. 1 As travellers from Toledo for the south generally have to wait some hours at Castillejo, it is not unlikely that some entomologist m a y find an opportunity of looking into tbis matter. The Spartium grows in quantity near the station. |
