Vol. XXXV.] 62 



be a very important factor in generic differentiation which 

 had been unnecessarily looked down upon and ignored. He 

 believed not only that colour-pattern in the nestling or 

 immature bird furnished in many instances an important 

 clue to the phylogenetic relationships of various groups of 

 species, but that, properly applied, it would in the adult 

 enable us to get a practical and working idea of the limiis 

 of genera. It would act in the way of a control experiment 

 by which we could substantiate or correct previous estimates 

 of generic groups which had been based on characters 

 ordinarily employed. Applied in a systematic way to all 

 genera throughout the whole class of Birds, he could not 

 help thinking that a great number of these genera would be 

 found either to include too many species or too few. 

 * * * ■3<- * -Sf 



Dr. Lowe said that the first few headings under which he 

 proposed to consider the subject would be of a general 

 nature, and the first point which he would like to lay stress 

 on was — 



(1) The distinction which must be made between colour- 

 pattern and mere coloration. 



Colour-pattern implied something of a deeper import than 

 mere shades and tones of colour — something which from its 

 constancy, its persistency, its independence of mere environ- 

 mental or climatic influences, and its co-relation with faunal 

 or geographic areas, appeared to undoubtedly suggest the 

 influence of the germ-plasm. If that were so, it obviously 

 followed that the factor of colour-pattern must be of 

 *' genetic " importance. It ought to be, as he believed in 

 many cases it was, a useful phylogenetic guide or clue. 



Mere coloration, on the other hand, or mere shades and 

 tones of colour, were of no genetic value. They were too 

 often purely adaptive or procryptic. They were exogenous 

 or autogenetic ; whereas colour-pattern was endogenous or 

 phylogenetic. As an example. Dr. Lowe quoted the case 

 of the European Goldfinch, which had been introduced into 

 the Bermudas only some fifty years ago, and yet had under- 



