184 THE MENDEL JOURNAL 



As is generally recognised, there are many different 

 kinds of single combs, and some of them are illustrated in 

 the authors' paper. Some are high, others low ; some are 

 erect and others lop over to one side ; some are prolonged 

 backwards in the form of a spur beyond their attachment 

 to the skull and others are not, but end, more or less 

 abruptly, at the hmit of their attachment ; some single 

 combs have many " points " and others few ; in some 

 the " points " are broadly triangular in form (Fig. 3), in 

 others the triangle is longer and narrower (Fig. 4), and in 

 others they are almost rectangular (Fig. 2). 



The authors seek to know whether these different 

 varieties of single comb may be hereditarily transmitted in 

 accordance with Mendelian principles when individuals 

 bearing them are bred together. They also desire to 

 learn, " how far from the normal in any direction the single 

 comb may be expected to depart in pure-bred birds ? " 



If these represent the objects which the authors had 

 in view when they commenced their investigation, we 

 feel forced to confess that we are a Uttle sceptical as to 

 the utility or validity of the methods employed. They 

 are, of course, typically biometrical methods and are 

 orthodox to the last letter of biometrical laAv. But, 

 unfortunately, that does not make them adequate or 

 vaUd instruments of biological research. As biological 

 instruments they are now quite antiquated, for biologists 

 have a more fruitful and modern method, that of the 

 genetic analysis of individuals by breeding experiments. 

 But if these objects are after-thoughts, inscribed when 

 the investigation was completed, and perhaps traced out 

 by the omnipresent sword-point of the biometrical 

 " Field Marshal," it will explain the existing incongruity 

 between the objects and the methods. 



The apparently real object of the investigators, that 

 with which they commenced their investigation, seems to 

 be contained in the following statement : "In this 

 paper we have endeavoured to give a clear and, as far as 

 possible, quantitative description of the nature and 

 amount of variation normally occurring in a homogeneous 

 pure-bred strain of Barred Plymouth Rock hens in respect 

 to the form and size of the comb." Now if this is the 

 precise object of the authors, then the methods adopted 



