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Show 532 MR. L. DONCASTER ON COLOUR-VARIATION [Dec. 12, the river-becl about two miles above Malaga, i. e. about a mile from the place just mentioned, but only a few feet above sea-level. There were only 25 males and 39 females (Table VI a), but they are of interest partly on account of the preponderance of females, and partly because the proportions closely resemble those shown in Table V., although the beetles were obtained from near sea-level, i. e. at the same kind of altitude as those from Palo. In this collection there were no plain greens. On April 7 collecting was interrupted for nearly three weeks, but on April 25 and 27 I was able in the short time at my disposal to obtain 23 males and 33 females at Palo (Table IV b). These numbers are too small to make possible a close comparison with the earlier gathering, but they are of importance from the fact that 12 of the males and 14 of the females were of the pure green type, usually with a yellowish tinge and nearly always brighter in colour than the green striped form. At the beginning of the month only 3 specimens of this type occurred in a collection of 377. On the 26tli I visited the bushes up the river-bed and gathered 23 males and 31 females (Table VI b), which included 4 males and 9 females of the pure green type, the proportions among the remainder being similar to those found on April 6. And on the 28th I obtained 40 males and 47 females from the road to the north (Table V b), and here again the plain green type was frequent, while three weeks before it had been almost absent. When I first arrived at Malaga I found that a beetle larva was common on the Spartium, and a couple which I kept alive both hatched to the pure green form of Gonioctena. It occurred to me that the green type might develop black pigment later, but several which I kept alive for a week showed no change of colour. Finally, when I was about to return to England, I gathered a quantity of larvae in the hope of bringing them back alive ; some of these came from Palo, where the predominant type was green, others from the north road locality, where the majority were red. The greater part died on the voyage, but I reared to maturity three of the Palo batch and eleven from the north road, and every one of these was plain green. There were 4 males and 10 females. I thought at Malaga that possibly the plain green type belonged to another species; and I attempted to find out whether it ever paired with the other forms, but was not successful. Very few, however, were pairing at that time, so no importance can be attached to the fact that I never found the two types paired together. On my return to England, Dr. Sharp very kindly examined some specimens of the green form and compared them with the spotted red, and reported that he believed they belonged to the same species. It must be concluded that as the season advances a new type begins to appear, and, judging by the fact that all the |
