88 Barboub 'v ;' v ,// cn. Thayer. [ian. 



a larger set of figures, found that there was no relative immunity 

 among the 'pencilled birds.' In fact, his figures rather favored 

 the solid colored birds. 



He shows (Amer. Naturalist, Feb. MM I. p. LI 7) thai "ever since 

 the tirsi description made My the Nurenburg miniature painter, 

 Mo-el, in I7l() of a case of presumably protective coloration, we 

 have been prone to argue that because an organism was colored or 

 formed in such a \\a\ as to be inconspicuous, it was therefore 

 necessarily protected from attack by its enemies to a greater or less 

 degree, The Logic oi such reasoning is flawless; it ought to be 

 protected, but a conclusion may be perfectly Logical and still not 

 true. Mi a study oi protective coloration, including mimicry, it is 

 essentia] that a discovery that an organism is to human eyes in- 

 conspicuous, or not readily distinguishable from some other organ- 

 ism, shall not Mo considered tho final civil. Let such a discovery Mo 

 supplemented by an experimental or observational determination 

 oi whether this inconspicuousness really helps tho organism in 

 actual practise in avoiding elimination by natural enemies." In 

 mam cases we have no theories to substitute for those oi Thayer, 

 but \\o do not hesitate, however, to say that tho burden of proof 

 rests on him. Tho evidence is all against him. though it is for tho 

 most part oi a negative sort. Meagre ami negative as it is. how- 

 ever, it is worth a great deal more than pure, unfounded speculation 

 based upon what is soon by a trained man's eye interpretating 

 animal vision. Thayer's color experiments are not really scientific 

 experiments in any biological sense. They are mathematical 

 demonstrations in human optics, pure physics and nothing else. 

 \- aesthetic, physical demonstrations, they are of great interest, 

 bin as to their interpretation in terms oi the organic universe they 

 are oi little interest and of no value. Thayer's point of view is 

 summed up in one sentence of his own words (Pop, Sci. Monthly. 

 ■Mil\ MM 1. p. 35] "1 have been studying for years to find out the 

 exact -cone that each costume Most represents, and I now beg my 

 readers to come to Monadnoek and let me show thorn tho results,' 1 



The evidence in Stunner's paper (Jour. F.xp. Zool. May 20, MM 

 regarding the color response of flat fish, when placed on different 

 background Moth natural ami artificial, is a model which Mr. 

 Thayer might well study. Stunner, thomrh he has seen at first 



