Volume VII MAY, 1918 No. 3 



ON THE STERILITY OF HYBRIDS BETWEEN THE 

 PHEASANT AND THE GOLD CAMPINE FOWL. 



By D. W. CUTLER, M.A. (Cantab.), 

 Assistant Lecturer in Zoology, Manchester University. 



(With Plate IX.) 



Our knowledge of the changes that occur in the constituents of the 

 nucleus during the maturation of the reproductive cells of animals and 

 plants, renders the cytological study of the gonads of hybrids of great- 

 interest and importance. However, it is only within comparatively 

 recent times that such investigations have been undertaken. Guyer's 

 work on the gonads of hybrid pigeons was one of the first made, and this 

 has been followed by the publication of the results of research on other 

 hybrid material. 



In 1915 Dr Doncaster and I published the result of investigation of 

 the testes of a sterile tortoiseshell cat. The condition of the organ was 

 so interesting in comparison with that found in other cases of sterility, 

 that I very gladly undertook to study the gonads of some hybrid birds 

 kindly given to me by Dr Doncaster. The progress of the research has 

 been slow owing to the pressure of other work and some of the problems 

 connected with it still remain unsolved. I have, however, been able to 

 discover the cause of sterility, which seems to justify the publication of 

 this paper. 



Material. 



The hybrids were bred by the Rev. Lewis Jones, who crossed pheasant 

 males with hens of the Gold Campine breed. About a dozen chicks were 

 obtained, which were of two kinds : 



(a) dark variety, (6) light variety. 



Joum. of tren. vii - 11 



