. 



GREAT STEPS IN EVOLUTION 103 



at once the grandeur and the difficulty of 

 each of its greater uplifts. 



EVOLUTION AS RETROGRESSIVE : DETERI- 

 ORATION AND PARASITISM. Of " Degenera- 

 tion: a chapter in Darwinism," Sir Ray 

 Lankester many years ago wrote a whole 

 volume, compact yet readable : still, even 

 to-day, the old optimism of political progress 

 too largely colours the public mind ; so, 

 despite knowledge and care, all save the most 

 pessimistic of us tend sometimes to speak, 

 and it may be even write, as if evolution 

 necessarily implied progress, and as if the 

 surviving fittest were also the best, in its 

 ordinary sense, of better than mere good. 

 Hence the need of frankly facing some of 

 those ugly chapters of natural history which 

 follow the decline of so many forms of life, 

 even high and beautiful ones, into degenera- 

 tions well-nigh incredible, into parasitisms 

 even loathsome. For one thing, even the 

 most thoroughgoing creationist and Paleyan 

 of old must have had some qualms in ascribing 

 the intricacies of parasitism to special creation, 

 or its pains and enfeeblement, so varied and 

 so widespread among all the higher animals, 

 to beneficent design; thus the evolutionary 

 parasitologist has had it practically all his 

 own way, yet has also cured us, with his 



