COMBS OF FOWLS 185 



by them to achieve it demonstrates at once the wide 

 and inseparable gulf between the methods of the Bio- 

 metricians and those of the Mendelians. The object is to 

 ascertain the natvire and amount of variation of the single 

 comb. Now to do this we must have perfectly homoge- 

 neous material in respect of the character which we are 

 investigating. We must be sure that the combs we 

 measure belong to one gametic entity ; they must be all 

 members of a definite, single gametic type. Otherwise, 

 we shall not be deahng with true variation at all, but 

 merely ^^^th an eidoscopic display of aggregated types. 



Now Dr. Raymond Pearl has investigated the problem 

 with biometrical methods, and the appearance of his 

 paper in " Biometrika " must be accepted as evidence that 

 from the standpoint of the hierarchy of Biometricians it 

 is accurate in method and sound in conclusion. We are 

 not, therefore, commenting upon Dr. Pearl's work in any 

 other sense than that we desire to examine the validity 

 or scientific utihty of the biometrical instruments which 

 he has employed in his investigation. Could we assent 

 to his methods we might commend his results ; we can 

 admire his skill as a workman, while lamenting his tools. 

 We shall, therefore, consider his paper as a ripened 

 product of Biometry, and as one written by, shall we say, 

 " an ardent " Biometrician. 



The object then before us is a study of the range 

 and nature of the variation in the single comb of a certain 

 race of hens. Now it must be confessed that were we as 

 Mendehans about to undertake this investigation the 

 first thing we should endeavour to obtain would be a 

 homogeneous race of combs and not of hens. It is in 

 this matter that we think the Biometricians have invali- 

 dated at the outset the value of any conclusions they 

 may reach. They have endeavoured to obtain what 

 they call " a homogeneous pure-bred strain of Barred 

 Plymouth Rock hens." Now is it possible to obtain 

 such a thing as a homogeneous race of individuals 1 In 

 pre-Mendelian days — that is, previous to 1900 — the term 

 pure bred had quite a diiferent significance to that now 

 attached to it by Mendelians. And, in its older sense, it 

 is still employed by fanciers. We know now that a bird 



