•M) THE AMElilCAS MI'SEIM JOlJiXAE 



position of aiict'stor to the intellifieiit life which was to ai)pear in the tiini 

 future. But tlie insect liad fulfilled the mechanical j)ossil)ilities of which 

 his structural organization was capable. The future prof^ress of the insect 

 type was to lie not in the direction of a more perfect mechanism, but in the 

 perfection of the metamorphosis durinji; the growth of the individual and 

 in the establishment of elaborate social organizations and instincts. 



The amphibian was but begimiing the adaptation of the vertebrate 

 structure to a terrestrial habitat and in his organization lay concealed a 

 potential evolution to a far higiicr plane of existence than the insect organ- 

 ization has been able to reach. It is not so easy to say just wherein this 

 superiority lay, but probably the possession of an internal instead of an 

 external skeleton was an essential feature of it. The late Professor Shaler ^ 

 has pointed out the advantages of an internal as against an external skeleton 

 in stimulating more intelligent and less blindly instinctive activities in the 

 evolution of animal life. The internal skeleton has also certain marked 

 mechanical advantages in permitting the attainment of a much larger size 

 in the animals possessing it, as may easily be seen by comparing the maxi- 

 mum size attained in one or the other type of organization under the same 

 conditions of life. 



" REVEALING AND CONCEALING COLORATION IN BIRDS 

 AND MAMMALS" BY THEODORE ROOSEVELT 



THIS book, jjublished l)y the Museum in August is well worth reading 

 by all interested in the subject of animal coloration. The more 

 than one hundred pages present a critical review of Thayer's 

 Concealing Coloration in the minimal Kincidom published in 1910. 



Mr. Roosevelt considers the principle of countershading a discovery, 

 of real merit as a colorist law but Avith limited application to birds and 

 mammals as far as concealment is concerned. From his extended experi- 

 ence in the field, he holds that this concealment is due mainly to " co\er 

 and habits." With pithy arguments and forceful examples, with now and 

 then an admission that the knowledge is incomplete and a frank, " I do not 

 know," he covers Thayer's points, separating misinterpretations from com- 

 mon-sense facts and deductions. The last sentence of his conclusion 

 summarizes his view. 



" As regards the great majority of the .species [of birds and mammals], the 

 coloration, whether concealing or not, is of slight importance from the stand- 

 point of jeoparding or preserving the bird's or manmial's life, compared to 

 its cunning, wariness, ferocity, speed, al)ility to take advantage of cover and 

 other traits and habits, and compared to the character of its surroundings." 



' The Individual: a Study of Life and Death. N. S. Shaler. New York: Apple- 

 tons, 1900. 



