PROGRESS, BIOLOGICAL AND OTHER 1 1 



environment than the flea which lives upon him as 

 a parasite, or than the bacillus which kills him, nor 

 is a bird better adapted to air than a jelly-fish to 

 water; therefore we have no right to speak of one as 

 higher than the other, or to regard the transition 

 from one type to another as involving progress." 



A second class of objector is prepared to admit 

 that there has been an increase of complexity, an in- 

 crease in the degree of organization during evolu- 

 tion, but refuses to allow that increase of complexity 

 has any value in itself, whether biological or phil- 

 osophical, and accordingly refuses to dignify this 

 trend towards greater complexity by the name of 

 progress. 



Yet a third difficulty is raised by those who ask us 

 to fix our attention on forms of life like Lingula, the 

 lamp-shell, which, though millions of years elapse, 

 do not evolve. If there exists a Law of Progress, 

 they say, how is it that such creatures are exempt 

 from its operations? 



Finally, a somewhat similar attitude is adopted by 

 those who refuse to grant that evolution can involve 

 progress when it has, as we know, brought about 

 well-nigh innumerable degenerations. Granted, for 

 instance, they would say, that the average Crusta- 

 cean is in many ways an improvement upon the 

 simple form of life from which we must suppose that 

 it arose, yet we know that within the group of Crus- 

 tacea there are several lines of descent which have 

 led to the production of parasitic forms — animals in 



