440 Rio l.uliy 



\- was to be expected t ho treatment in this work is thoroughly scientific. 

 The spectrum is divided into 36 colors which run in oblong blocks a. 

 the middle of the first twelve plates, three shades to a plate. Immediately 

 above these is another series of 36 colors each one differing from it s respec- 

 tive spectrum color by a definite admixture of white. Uv\ e these are two 

 more series each with :\ larger proportion of white while below the spec- 

 trum colors are three series of shades differing from the tatter by successh e 

 admixtures of Mark. We have therefore si\ shades based upon each of 

 the 36 spectrum colors ranging upward toward white and downwards 

 toward black. 



Beginning with plate 13 we have the whole series over again with a 

 definite proportion of neutral gray added to each of the 216 shades, and on 

 the following plates additional series with two. three, four and five propor- 

 tions of neutral gray addod. As the whole scheme gradually tends toward 

 ;\ uniform gray tint the number of shades that are distinguishable decn 



e advance so that the latter series do not contain as many blocks as the 

 earlier ■ 



Everj one of the 11 15 shades is named and Mr. Ridgway has searched 

 the literature and even trade catalogues for color names already in use. 

 While the shades represented seem to ho about all that the average eye 

 can distinguish, nevertheless the author finds that 36 of the named colors 

 in this former ' Nomenclature ' fall between some of those here depicted, 

 consequently they are dropped and their true position indicated in a 

 table. Unfortunately many well known names fall in this way. but orni- 

 thologists who have seen so many familiar generic and specific names sink 

 into oblivion can probably part with such terms as ' buff,' ' canary yellow .' 

 lire blue." ' oohraoeous.' 'vermilion,' 'violet.' etc. without serious 

 inconvenience. Indeed the use of some of these names like that of the 

 discarded technical terms has been so abused that it is better after all to 

 i them. 



\ omplete catalogue of color names with plate reference makes it easy 

 to find any shade that may be referred to. while an understanding of the 

 arrangement oi the plates enables one to find all the ' rods ' or ' blues ' 

 without delay for purposes of comparison. 



The whole plan is discussed in detail in the ' Prologue ' with reference to 

 various works dealing with the subject. 



In order to avoid the possibility of variation in the tints in the individual 

 eopios. each color, for the entire edition, was painted uniformly on largo 

 shoots of paper from a single mixture of pigments, those shoots being then 

 out into the small oblongs which represent the colors on the plates. 



Mr. Ridgway's volume forms a color standard which is about as nearly 



perfect as it can probably bo made. It is absolutely indispensable to the 



working naturalist not only as a guide to the nomenclature of his own 

 descriptions, but as a key to the descriptions of others. That it will long 

 remain the standard work of its kind goes without saying and both natura- 

 lists and artists should bo deopb grateful to Mr Kidgway for the years oi 

 labor that ho has expended upon this work. — W. S. 





