Sun-birds 



67 



of the plumage in both sexes is also dull, but, besides 

 the yellow pectoral tufts of the male, there is also a further 

 development of metallic colour, which here extends to 

 the forehead as well as the throat. In the male of C. 

 reichoibachi (Fig. 3) we find a plain-plumaged species, but 

 with still more metallic decoration than in C. cyanoUeinus, 

 for it extends not only over the crown of the head but 

 over the sides of the face, throat, and fore-neck, while 

 as usual the pectoral tufts are still in strong evidence; 



2. The male of T. cyanplo'iinis. 3. The male of T. 7>:ichcnbaclu. 



and other species can be quoted in which a gradual 

 development of metallic colour has taken place in the 

 male, until we meet with the beautiful C. splendidus here 

 figured, which rivals any Humming-bird in the beauty of 

 its metallic tints. If there is any possibility of the correct- 

 ness of such a theory of development as I have indicated, 

 the question may be asked : Is there a species known 

 in which both sexes are alike, and in which the male 

 resembles the female in plumage? I am able to state that 

 there is such a species, in fact more than one, so that 

 we may imagine that these represent some of the original 

 and ancient forms of Nectariiiida;, in which the sexes 

 were alike plain-coloured, and the metallic plumage has 

 been gradually evolved by sexual selection or some other 

 cause to their present beautiful livery. Such olive-coloured 

 species exist in C. olivaceus of South Africa and C. obscurus 



