THE ENTOMOLOGIST 



Vol. XXXIIL] JULY, 1900. [No. 446. 



COLLECTIVE INQUIRY AS TO PROGRESSIVE MELANISM 



IN MOTHS. 



The following " Memorandum from the Evolution Committee 

 of the Roj-al Society " has been recently issued : — 



1. The Committee appointed by the Council of the Eoyal 

 Society to promote investigation of facts relating to Variation, 

 Heredity, Selection, and other phenomena connected with 

 Evolution are desirous of instituting a collective investigation 

 into the progressive melanism of certain moths, particularly 

 Geometridae. 



2. It is well known that in certain districts, especially within 

 the British area, dark forms of several species of moths have 

 recently appeared and become increasingly abundant. There is 

 reason to believe that these dark forms are in some cases ex- 

 tending into other districts and even to the European Continent. 



3. It is to be regretted that no systematic or statistical 

 records of these phenomena have been kept, and it appears to 

 the Committee that if such a record be now instituted and 

 continued for a period of years it cannot fail to have considerable 

 scientific importance. 



4. The matter is one that may conveniently be made the 

 subject of collective investigation, and the Committee will be 

 glad to hear from any entomologist who may be willing to 

 contribute now, or hereafter, particulars as to the condition of 

 these species in the district or districts with which he is person- 

 ally familiar. The returns should relate as far as possible to 

 specimens found in a wild state, whether as imagines, or pupse, 

 larvae, or eggs. Information respecting specimens bred from 

 wild parents must be kept distinct. 



5. It is tbought desirable that the enquiry should for the 

 present be confined to the following species : — Acidalia avcrsata, 

 Amphidasys bctularia, Boarmia repandata, Camptogramma hilineata, 



ENTOM. — JULY, 1900. R 



