RECOG^^ITION-MARKS 



>-^7 



177 



terised bj spots or bands, or caps of brilliant or contrasted 

 colours. But as these usually break up the green body into 

 irregular portions, and as flowers of equally varied hues are 

 common on trees, or on the orchids and other epiphytes that 



Fig. 38. — (Edicnemus recurvirostris (Great Indian Stone-Curlew). 

 This species is found all over India, and also in Ceylon and Burma. This species 

 is clearly defined by the upturned bill and the compact black mark around the 

 eye. 



grow upon their branches, the general effect is by no means con- 

 spicuous. 



]^ow, without this principle of the necessity for external 

 differences for purposes of recognition of each species by their 

 own kind, and especially of the sexes by each other, this end- 

 less diversity of colour and marking, when not protective, seems 

 difficult to explain. The Duke of Argyll, in his interesting 

 work, The Reign of Law, published six years after the Origin 

 of Species, expressed this objection very forcibly. After de- 

 scribing many of the wonderful forms and ornaments of the 

 humming-birds, he says : 



" Mere ornament and variety of form, and these for their own 

 sake, is the only principle or rule with reference to which Creative 

 Power seems to have worked in these wonderful and beautiful 

 birds. ... A crest of topaz is no better in the struggle for 

 existence than a crest of sapphire. A frill ending in spangles of 



