VARIATION. 41 



Vanessa io. — Hybernated specimens, though common in the spring, 

 were not so abundant as in 1906. They were observed from March 

 26th until June 16th. No larvse were met with and this year's 

 imagines were rather scarce and very late, none appearing until 

 September 8th, more than a month later than last year. 



Pyraiiieis canlui. — It is rather curious, considering that 1906 was 

 decidedly a " canlui year," that this is the first season, since coming 

 to this district in 1904, we have failed to meet with this insect. 



P. atalavta. — I have not seen a single example of this butterfly 

 this season, but heard that one was seen flying in the garden about the 

 second week of September. 



A Biological Inquiry into tlie Nature of Melanism in Amphidasys 

 betularia, Linn, {irith plate). 



By H. S. LEIGH. 

 In connection with an investigation which I am making on the 

 "melanism" of Auifihidasi/s betularia with a view to elucidating, so far 

 as is possible by experimental and statistical methods, the causes which 

 operate in the production of melanic forms, it is intended to make an 

 extensive enquiry as to the distribution, etc., of the typical, inter- 

 mediate, and melanic forms of this species. I should be extremely 

 grateful if entomologists would assist me in collecting the information 

 concerning the occurrence and distribution of these forms by answering 

 as many as possible of the subjoined questions. 



1. Whether form A or form D occurs in a particular locality. 



2. If both forms occur state, if possible, the actual numbers taken 

 of each, or state which form predominates and to what extent. 



3. State whether forms B or C occur and in what abundance. 

 Give exact localities where each form occurs. 



4. State the atmospheric character of the district, and whether it 

 is rural with a smokeless atmosphere, or urban and smoky, or inter- 

 mediate in character. Any other information of a general character 

 will be very acceptable. 



Replies to these queries on postcard, may be sent to H. S. Leigh, 

 Zoological Department, The University, Manchester. 



[We trust that as many lepidopterists as possible will give Mr. 

 Leigh the desired information, and so facilitate his inquiries into this 

 interesting subject. — Ed.] 



^^ AR I A T 10 N . 



The Vakiation of Xylophasia rurea. — The editorial query to my 

 note on the breeding of Xylajiliasia rurea {antea p. 17) has led me to 

 enter into rather more detail with regard to the aberrations bred. 

 Altogether I took rather over 100 larva^ of this species, of which about 

 90 produced imagines, chiefly during the last week in June. Of these 

 about one-third possessed markings like the type, the other two-thirds 

 were more or less brown. I sent the pick of them to Mr. Hanbury, 

 who wanted to renew his series, bat, of those I put in my collection, I 

 note the following : Three each with typical markings, but with three 

 shades of ground colour which appear to correspond with (1) the type 



