Vol. xxxr.] 64 



(2) The question of concealing coloration and vice versa, viz. 

 brilliancy of coloration. 



There were all sorts of pretty theories in this connection ; 

 but it seemed to him that, if concealing coloration was really 

 the universal plieuomenon it was made out to be, we ought 

 to find that, as a general rule, there was afar greater, a more 

 universal, and a more intimate commingling of every kind 

 of procryptic colour, irresjjective of ivell-dijferentiated groups 

 of birds. Instead of this, we found that certain distinctive 

 colour-schemes were characteristic and proper to certain 

 families or genera of birds, quite irrespective of the fact 

 that such groups of birds were exposed to precisely similar 

 environments. Briefly stated, one got the impression in 

 trying to analyse the colour-factors characteristic of families 

 or genera that in such groups the ancestral germ-cells had, 

 so to speak, two or three colour-factors to " play with '^ and 

 make the best of. All the germ-cell, or the chromosomes, 

 could do was to produce variations with the particular colour- 

 factors originally allotted to them. If these variations were 

 not flagrantly out of harmony with the environment, all was 

 well and good. 



Dr. Lowe then illustrated his remarks by an excellent 

 diagram which represented the two dividing branches of the 

 family Drepanididae of the Sandwich Islands. He assumed 

 that Oreomystis bairdi, in which the bill was the least special- 

 ised and the colour, both in male and female, a complex of 

 neutral shades of olive-brown or olive-grey, was the most 

 ancestral living representative of this family. It was the 

 most generalised and adaptive of all the species. Granting 

 this, we might suppose that in the germ-cells of this species 

 or its ancestors there were resident three potential colour- 

 factors — red, yellow, and black. Out of these colour-factors 

 the colour-scheme cliaracteristic of exerj genus of the family 

 could be constructed by various combinations of these 

 primary colour-factors, the factor of black being presumed 

 to be independently distributed. 



In connection with the subject of particular groups of 



