54 DARWINISM TO-DAY. 



by flying splinter, or the complete decay of a little spot due 

 to fungus growth ! A general and sufficient seeming of a 

 dead leaf, object of no bird's active interest, yes, but not a 

 dead leaf modelled with the fidelity of the wax-workers in 

 the modern natural history museums. When natural selec- 

 tion had got Kallima along to that highly desirable stage 

 when it was so like a dead leaf in general seeming that 

 every bird sweeping by saw it only as a brown leaf clinging 

 precariously to a half-stripped branch, it was natural 

 selection's bounden duty, in conformance with its obligations 

 to its makers, to stop the further modelling of Kallima and 

 just hold it up to its hardly won advantage. But what 

 happens ? Kallima continues its way, specifically and ab- 

 surdly, dead-leafwards, until to-day it is a much too fragile 

 thing to be otherwise than very gingerly handled by its 

 rather anxious foster-parents, the neo-Darwinian selec- 

 tionists. 



An objection which was long ago pointed out, and which 

 has been emphasised strongly by some biologists and almost 



overlooked by others, is that of the incom- 

 too^htuVgTv'e P atibilit y of the results concerning the age of 

 selection oppor- life on this earth as propounded by physicists 

 workf ' an d astronomers with the demand made by the 



theory of descent. This objection of the lack 

 of time for the production of the hosts of kinds of plants 

 and animals through the slow workings of natural selection 

 was brought forward against Darwin from the very begin- 

 ning and has never been given up. De Vries, 28 for example, 

 in a recent paper, refers to it as follows : 



"The deductions made by Lord Kelvin and others from the 

 central heat of the earth, from the rate of the production of 

 the calcareous deposits, from the increase in the amount of 

 salt in the water of the seas, and from various other sources, 

 indicate an age for the inhabitable surface of the earth of 

 some millions of years only. The most probable estimates 



