126 REPORTS ON THE STATE OF SCIENCE. 



spring which include, in addition to yellows, a proportion of individuals 

 whose colour is other than yellow. 



Yellow X yellow (25 ma tings) = 53 28 



Yellow X other colours (53 matings) = 124 113 



The anomalous heredity of the yellow coat colour in mice is thus con- 

 firmed. 



(2) In the matings yellow x yellow the proportion of yellow to 

 non-yellow individuals in the F l generation is 2 : 1 instead of the familiar 

 3:1. This harmonises with the results of Cuenot, Castle, and Durham, 

 and suggests that the yellow -bearing gametes do actually conjugate, but 

 that the zygotes so produced perish. 



(3) In harmony with the latter suggestion is the fact that the 

 number of mice in a litter, when both parents arc yellow, is less than 

 when either or both of the parents are of some other colour: — 



Average No. 

 of young 



Yellow X yellow (25 matings) 3-64 



Yellow X non-yellow (53 matings) 4-75 



Non-yellow X non-yellow (103 matings) 4-75 



Matings in which one or both parents are albino are not included. 

 This quite marked difference is not found by Miss Durham in the mice 

 which she bred, but is in agreement with the observations of Cuenot and 

 Castle. 



(4) In the matings yellow x other colour the F x generation shows 

 the expected normal approximate equality of yellow and other coloured 

 individuals. 



The above results, and certain others, will, it is hoped, be set out 

 in detail during the present year. The Committee therefore ask to bo 

 reappointed for one year without a grant. 



The Formulation of a Definite System on which Collectors should record 

 their Captures. — Report of the Committee, consisting of Professor 

 J. W. H. Trail {Chairman), Mr. F. Balfour Browne (Secretary), 

 Dr. Scharff, Professor G. H. Carpenter, Professor E. B. 

 Poulton, and Mr. A. G. Tansley. 



The Committee were appointed last year and have dealt with the matter 

 by correspondence. They have decided that the Watsonian County 

 and Vice-County system should be recommended, but the details are 

 still under discussion and it is proposed, before issuing a final report, 

 to consult the field clubs and natural history societies of Great Britain 

 and Ireland with a view to acquainting them with the ideas of the 

 Committee and hearing from them any suggestions they may be 

 inclined to make. 



The Committee therefore ask for reappointment. 



