65 [Vol. xxxT. 



birds having particular colours characteristic of them. 

 Dr. Witmer Stone had recently called attention in America 

 to the absence of red among the Jays or of green among 

 the Thrushes. He had also called attention to certain 

 conspicuous colour-patterns difficult to reconcile with any 

 plan for concealment or with any scheme of a ruptive nature. 

 Such were the metallic blue and green specula in the Ducks 

 or the blue and black wing-patch in the Jays. 



Dr. Lowe said he was not in these remarks trying to 

 belittle the patent and manifest facts of concealing coloration. 

 He was not quarrelling with Thayer's theory of counter- 

 shading as far as it went ; nor was he saying that certain 

 colour-patterns did not serve a useful ruptive purpose. 

 What he did think was^ that the protective-coloration idea 

 was in danger of being ridden to death. It was only one 

 phase of the whole question of coloration, and, taking 

 the class of birds as a whole, it had probably always 

 been, so to speak, a more or less lucky chance, if colour- 

 pattern born of genetic influence happened to coincide with 

 such a desirable end as invisibility or concealment. 



The idea in the past was that colour-patterns had been 

 invariably and directly impressed on the birds' plumage 

 through the agency of environmental stresses, aided by 

 natural selection, and hence systematists had naturally 

 fought shy of using such a character in classification. But 

 there was the other side of the picture. 

 Another aspect of the case was 



(3) The constancy and persistence of colour-pattern. 



To illustrate this Dr. Lowe again quoted the case of the 

 Ringed Plover group (^gialitis), and drew the attention of 

 members to an enlarged drawing representing three genera 

 of East Indian Cuckoos — Dryococcyx, Rhinococcyx, and 

 Urococcyx (taken from Dr, Witmer Stone's paper), — in 

 which the colour-pattern was seen to be constant, in spite 

 of conspicuous structural generic and geographic differenti- 

 ation. He also exhibited five genera of the larger Caciques 

 or Oropendolas of the family Icteridae, in which the colour- 



