226 Reviews. [J^,, 



in climate are so great, according to elevation, humidity, &c., 

 that the same species in different localities are bound to undergo 

 some degree of evolution, which shall render them suitable to their 

 surroundings." He accepts geographical variations " as sufficient 

 reason for the creation of sub-species as long as they are constant 

 within a given area, though intermediate areas may be inhabited 

 by intermediate forms." 



The coloured plates, from drawings by H. Gronvold and G. E. 

 Lodge, deserve the highest praise. They are a delight to the 

 eyes. The printing and binding of the volume are also excellent. 

 If such a work on Australian Pigeons and Doves could be pro- 

 duced at a reasonable cost it would be warmly welcomed by 

 members of the R.A.O.U. 



["Colour Standards and Colour Nomenclature." By Robert Ridgway, 

 M.S., C.M.Z.S., &c., Curator of the Division of Birds, United States National 

 Museum. With fifty-three coloured plates and eleven hundred and fifteen 

 named colours. Washington, D.C., 191 2. Published by the author.] 



The author, who is an honorary member of the R.A.O.U., has 

 kindly sent for its library a copy of this useful book, with the 

 following note : — " A year or so ago I promised to send you, 

 when the book was published, a copy of my ' Colour Standards 

 and Colour Nomenclature ' for review in The Emu ; but my time 

 lias been so fully occupied, chiefly by the preparation of part vi. 

 of ' Birds of North and Middle America,' that many things have 

 necessarily been deferred. ... As information for your 

 readers, I will state that the sole agents for the sale of the book 

 in Europe and the British Colonies are WilHam Wesley and Son, 

 28 Essex-street, Strand, London, W.C, and that the price is 



£1 15s." 



Professor Ridgway's gift is very acceptable and easily acknow- 

 ledged, but to criticise it is another matter. The critic may well 

 say it is above criticism. The fifty-three plates are a technical 

 triumph. Each has gradations of tints or shades shown by 

 21 small oblong shields of colour on a pale neutral grey mottled 

 background. One has to be possessed of a very discriminating 

 eye to separate the colours. Take, for instance, " mouse-grey." 

 On the light side there are " light mouse-grey," " pale mouse-grey," 

 and " pallid mouse-grey," while on the dark side there are 

 " deep mouse-grey," " dark mouse-grey," and " blackish mouse- 

 grey." And so on for over one thousand different colourations. 



The standardization of colours and colour names is of great 

 assistance to ornithologists in describing birds and eggs, and a 

 tremendous incentive to the trinomialist to multiply sub-species 

 on the slightest variation of shade or tint of colour. 



The highly technical introduction must be of fascinating 

 interest to students of chromatology and colour physicists. One 

 often hears mentioned " complementary colours." Defined by 

 the professor it means : — " ' As white light is the sum of all colour, 



