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THE AMERICAN XATURALIST 



[Vol. XLV 



not only type and variability but correlation 3 will be open for 

 investigation. 



Looking at the tables of constants, the cautious biometrician 

 will hesitate to say that Professor Rumpus has proved his point. 

 The data available are too scanty to justify dogmatic assertions. 

 But the work is so suggestive and the results so convincing that it 

 is difficult to understand why zoologists have not followed it up 

 by other studies of a comparable nature. To be sure, opportun- 

 ities of this particular kind do not occur every winter, but there 

 are other sources of elimination active in nature, and one of the 

 most important tasks before those interested in the problems 

 which Darwin pointed out to biologists, is to determine whether 

 the individuals which survive are able to do so because of certain 

 structural peculiarities, while those which perish are eliminated 

 because they are in the degree of development or in the correla- 

 tion of their parts structurally unfit. 



J. Arthur Harris. 



Brooks in his " Foundations of Zoology," Lectin-es VI-VTTT. and the 

 hypothesis of Crampton. in Jmtrn. Exp. Zool., 2: 425-430, 1905. 



