56 DARWINISM TO-DAY. 



cooling of a sphere of the size and composition of the earth). 

 They have assumed that its material is self-cooling. But 

 as Huxley pointed out, mathematics will not give a true 

 result when applied to erroneous data. It has now, within 

 the last five years, become evident that the earth's material 

 is not self-cooling, but on the contrary self-heating, and 

 away go the restrictions imposed by physicists on geological 

 time. They are now willing to give us not merely a thou- 

 sand million years, but as many more as we want." 



In this connection should be mentioned the position taken 



by Ammon 3 and others who argue that the real effect or 



Claim that se- resu ^ ^ natural selection is to preserve the 



lection hinders type at the expense of the variants, which would 



rather than pro- . 111 i r 



motes species- make it a retarder rather than accelerator of 

 change, species-change. Bumpus's 3 observations on, 



and conclusions concerning, his storm-beaten English spar- 

 rows is an example of what Ammon claims must be the 

 real result of selection. Bumpus, in statistical studies of the 

 variation of two animal species introduced from Europe into 

 the United States, viz., the English sparrow and the peri- 

 winkle, Littorina littorea, shows that the eggs of the sparrow 

 and the periwinkles themselves are much more variable in 

 ,j America than in their native regions, and the au- 



Bnmpus's ob- 

 servations on thor attributes this increased variability to their 



"presumable emancipation from many of the re- 

 straining influences of natural selection." In the case of the 

 English sparrows, also, Bumpus believes himself able to 

 show on a basis of the examination of 136 birds brought 

 in wounded or stunned after a severe storm of snow, rain, 

 and sleet (Feb. I, 1898), that the sixty-four birds that 

 perished (seventy-two revived), "perished not through acci- 

 dent, but because they were physically disqualified, and that 

 the birds which survived, survived because they possessed 

 certain physical characters. These characters enabled them 

 to withstand the intensity of this particular phase of selective 



