ZOOLOGY. 421 



Lubbock lias studied this matter from a statistical stand- 

 point, and finds that out of eighty -eight spiny and hairy 

 species tabulated, only one is green (X. sybilla), while a very 

 great majority of the black and brown caterpillars, as well 

 as those more or less marked with blue and red, are either 

 hairy or spiny, or have some special protection. His results 

 confirm, in a remarkable manner, he thinks, the conclusions 

 previously arrived at by the naturalists he names. 



An interesting case of natural selection is described by 

 Mr. S. F. Clarke in the American Naturalist. The writer 

 obtained a large number of eggs of a salamander (probably 

 Amblystoma opacum). They were hatched in due season, 

 and then began, for want of proper food, to develop canni- 

 balistic tendencies and to eat off one another's gills. It was 

 discovered that among the many there were a few which, 

 though they came from the same parents and w^ere subjected 

 to the same conditions while in the e^Gf, w T ere vet gifted 



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with greater vigor and energy than most of their brothers 

 and sisters. These few stronger ones ate off the cills of 



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many of the w r eaker ones, and, at the same time, were enabled 

 to protect their own from mutilation or destruction. These 

 favorable conditions the large supply of food and the bet- 

 ter aeration of the blood soon beo-an to show their influ- 



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ence upon the growth of the individuals thus favored. With- 

 in a week or ten days from the escape from the egg these 

 favored few were fifty per cent, larger than their weaker 

 comrades who were born upon the same day. "Their 

 mouths had by this time increased so much in size that 

 they were no longer satisfied with nibbling off the gills of 

 their brethren, but now began to swallow them bodily. This 

 great increase in the supply of food soon produced a marked 

 effect upon those who were thus supplied ; so that in ten 

 days from the time that they began to feed in this way they 

 were from ten to twelve times the length and bulk of those 



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upon whom they were feeding. Developing at this rapid 

 rate, thev arrived at the stasre when the 2;ills are resorbed 



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and the abranchiate form leaves the water for the marshy 

 land or old, damp log, where it usually makes its home, and 

 where it would find a supply of more natural food material. 

 Here, then, was a very interesting case of natural selection 

 by survival of the fittest: all the weaker individuals being 



