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III. Pedigree Moth-breeding, as a means of verifying 

 certain important Constants in the General Theory 

 of Heredity. By Francis Galton, F.B.S. 



[Read February 2nd, 1887.] 



It was suggested by Mr. Merrifield, in answer to my 

 inquiries, that moths, especially those which breed 

 normally twice in the year, would be very suitable 

 subjects for a course of such experimental breedings as 

 I have long desired to establish. My object at the 

 present time is to obtain data for the revision and 

 extension of a general theory of simple heredity, on 

 which I have lately published memoirs,* and especially 

 to test that portion of it which relates to Stability of 

 Type. In addition to this, the experiments I propose 

 would elicit incidentally many interesting results, some 

 perhaps quite disconnected with the objects immediately 

 in view. 



The merits of moths as subjects of experiment are 

 that the arrangements for breeding them in large 

 numbers occupy comparatively little space, and involve 

 comparatively little cost ; their generations succeed each 

 other quickly, and they undergo no change in length or 

 shape of wing, &c, during their brief lives, so that the 

 difficulties elsewhere connected with age and growth 

 disappear ; the specimens that are used in the experi- 

 ments can be afterwards mounted in cases, and be 

 labelled and preserved for future reference. 



Mr. Merrifield has very kindly offered to commence 

 the experiments for me, and trusts to be able to continue 

 them for some years. I lay the proposed plan before 

 the Entomological Society in hope of eliciting the 

 suggestions and help of its members before the course 

 of experiments is fairly begun. 



:;: "Law of Regression," Journ. Anthrop. Inst., 1885; "Family 

 Likeness in Stature," Proc. Royal Soc, 1886; "Family Likeness 

 in Eye-Colour," Proc. Royal Soc, 1886. 



TRANS. ENT. SOC. LOND. 1887. — PART I. (APRIL.) 



