618 MESSRS. J. LEWIS BONHOTE AXD F. W. SMALLEY O^i 



and in addition to these the wpj^arently large predominance of 

 homozygous Chequers and heterozygous Grizzles. 



These questions have been very much before us during the 

 whole of our experiments, as indeed must be the case, for they 

 cannot fail to bring themselves to the notice of every practical 

 breeder. 



At the present moment we do not consider it advisable to 

 bring forward any attempted answers to these questions. Much 

 more woi'k yet remains to be done among the other colours, and 

 until we know moi-e of their inheritance any attempt to solve 

 these problems would be pi-emature. On the other hand, we are 

 not without hope that the further expeiiments in which we are 

 at present engaged may help to throw some light on these 

 perplexing problems. 



Suinmary, 



This paper may strike a reader as having for its main object 

 the confirmation of the Mendelian Laws ; that, however, is by 

 no means the case. Realizing that many details of inheritance 

 did not entirely accord with the Mendelian theory, our object has 

 been to extract, so to speak, from the results obtained by mating 

 on Mendelian lines, that portion of them which clearly shows the 

 Mendelian inheritance. The residue must, we submit, have been 

 brought about by some law or sei'ies of laws, which overrides and 

 modifies (externally at all events) the expected Mendelian results. 

 By means of this extraction we are able to see the effect of that 

 law or laws untrammeled by the effects of inheritance as rided 

 by the Law of Mendel, and thus we have been brought slightly 

 nearer to an understanding of them. 



Now this ]3aper deals with the Mendelian inheritance of the 

 characters considered ; consequently all details of shades of colour, 

 predominance of one sex in certain colours, and seveial other 

 similar matters have been entirely omitted. 



On the other hand, certain points such as the superabundance 

 of Chequers in our Chequer matings and of Blues in the Grizzle 

 and Blue matings, have had to be brought forward and the results 

 are, we hope, sufficiently conclusive to pi-ove to our readers that 

 although the characters dealt with follow in the main on the lines 

 of the Mendelian inheritance, yet it is equally certain that thei'e 

 is another factor which is able to dominate and influence that 

 inheritance. 



So far as the matter has been dealt with in this paper there is 

 no evidence to show that the gametic inheritance has been 

 affected. Except in one doubtful case (Exp. 181) we have not in 

 the course of all our matings bred a single bird that was not a 

 possible result of the mating under the strictest expectation of 

 the Mendelian theory. What, however, we have been able to 

 show is, that in certain cases a consistent deviation from the 

 expected proportions occurs. It would thus seem at first sight as 



