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X. Profjressive melanism on the Riviera (ffydrcs), being 

 further notes on Hastula hyerana, Mill. By T. A. 

 Chapman, M.D. 



[Read March 21st, 1906.] 



Plate VIII. 



Merely as further notes on the life history of Hastula 

 hyerana, Mill., the following facts would hardly have been 

 worth presenting, as an addition to the account of the species 

 I presented in the Entomologist's Monthly Magazine for 

 1905. Their value appears to lie in the further light they 

 throw on melanism in the species at Hyeres, and raise to 

 something like certainty, what was last year little more 

 than a suggestion, that melanism is a decided feature of the 

 species at Hyeres at present, though fifty years ago there 

 was no trace of it. That melanism really exists in the 

 Hyeres race of H. hyerana is shown by Mr. Powell having 

 reared 10 specimens at Hyeres, of which 4 were dark, 

 whilst from 10 larvae collected at the same time which he 

 sent to me in cocoon, and which were kept till emergence 

 in England, only 2 dark specimens appeared, the other 

 8 being of the pale (typical) form. This seems to show 

 clearly that the dark specimens I reared are naturally 

 melanic, and are in no way artificial results of removal to 

 the English climate. That such removal has no such effect 

 is also proved by the breeding at Reigate of specimens of 

 H. hyerana, from larvse collected in Sicily, every one of 

 which was of the typical pale form, with a good deal of 

 variation in dark marking, but with no trace whatever of 

 the melanic form. These Sicilian specimens resembled 

 very much the typical (pale) Hyeres form, so much so that, 

 omitting a few of the more marked varieties, they are 

 probably a fair representation of the Hyeres examples bred 

 fifty years ago by Milliere. I obtained also some larvae from 

 the Island of Capri ; these produced moths of a very pale 

 straw tint, with pale straw-coloured hind wings, possessing 

 only a trace in one or two, of the fuscous tint that is the 

 TRANS. ENT. SOC. LOND. 1906. — PART H, (SEPT.) 11 



