532 MR. L. DONCASTER ON COLOUR-VARIATION [DeC. 12, 



the river-bed 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, 

 bvit 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 gatheiing, 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 26th 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 Sjxirtiuin, 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 majoiity 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 veiy 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 



