Volume III APEIL, 1914 No. 4 



(1, 



ON HYBRIDS BETWEEN MOTHS OF THE GEO- 



METRID SUB-FAMILY BISTONINAE, WITH (^^Tvcrk 

 AN ACCOUNT OF THE BEHAVIOUR OF THE «'".av,c^* 

 CHROMOSOMES IN GAMETOGENESIS IN LYCIA 

 {BISTON) HIRTARIA, ITJIYSIA (NYSSIA) 

 ZONARIA AND IN THEIR HYBRIDS. 



By J. W. H. HARRISON, B.Sc, and L. DONCASTER, Sc.D. 



PART I. GENERAL ACCOUNT OF HYBRID BISTONINAE. 



By J. W. H. Harrison, B.Sc. , 



In the Entomologist for July 1910 I indicated that I had succeeded 

 in producing a number of new hybrids in the trio of genera included in 

 what may be called, for the sake of convenience, the Biston group. I did 

 not then, however, publish any details, either biological or otherwise, 

 concerning them. Since then, in the case of many of these hybrids, I 

 have worked out their detailed life history and have therein compared 

 them, point by point, with the parent species. Further, I have secured 

 several new and imj)ortant pairings ; not only is this so, but in the case 

 of most of them I have published an exhaustive account in Oberthiir's 

 Lepidopterologie comparee, Fascicule vii. pages 333 — 655. In case this 

 work is not readily accessible to English readers, I am writing this 

 summary of my results to accompany Dr Doncaster's statement of his 

 investigations into the oogenesis and spermatogenesis of Lycia hirtaria 

 and Ithysia zonaria, and their two crosses, hybrids denhami and 

 harrisoni. (Plate XVII.) 



The hybrids reared may be divided into two sections. 



(a) The Primary hybrids, i.e. those with pure species as parents. 



(6) The Secondary hybrids, i.e. those in which either of the two 

 parents was a primary hybrid. 



Journ. of Gen. iii 16 



