63 [Vol. XXXV ; 



gone such superficial changes in the direction of darker 

 tones and shades of colour that Mr. Kennedy had not 

 hesitated to differentiate it as a distinct subspecies. 



In contradistinction to this superficial change, Dr. Lowe 

 then dwelt upon the very constant type of colour-pattern 

 characteristic of the Ringed Plover association (^^gialitis). 

 In any one species of this group you had a thoroughly 

 stereotyped reproduction of the colour-pattern of any other 

 species, no matter how isolated those species might be, 

 whether they were exposed to differing environments or 

 whether thousands of miles of ocean separated one from 

 another; and what he wished to emphasise was this — Could 

 anyone seriously imagine for one moment that that particular 

 and constantly occurring colour-pattern was absolutely 

 indispensable for the continued existence of that particular 

 race of Plovers or ever had been? 



On the contrary — might we not surmise that that parti- 

 cular colour-complex or colour-tendency was originally 

 impressed on those Einged Plovers through the agency of 

 some purely fortuitous " shuffiing" of the chromosomes in the 

 germ-cells of some remote ancestor ? It was a colour-pattern 

 which had persisted, not because it owed its origin to any 

 formal plan for the protective concealment of these Plovers ; 

 but because the germ-cell, once started on a certain line, 

 could not help repeating itself in that direction, and because, 

 since the colour-tendency was not harmful to the race, 

 there was no excuse for any eliminating factor to suppress 

 either it or the race. Hence the germ-cell, or the jugglery 

 which took place within it, had gone on repeating itself — 

 and would go on repeating itself — until some sudden mutation 

 or re-shuffling of the chromosomes in the germ-cells of any 

 particular species started a new line of evolution in colour- 

 pattern. In such a case then as the colour-pattern typical 

 of the cosmopolitan Ringed Plovers he submitted that we 

 had a colour-complex which was endogenous or ''genetic^' 

 in origin. It was congenital. It could be used as a generic 

 test or character. Again there was 



