102 PROBLEMS OF EVOLUTION 



not trustworthy as transmitters of race-character since they are 

 sprung from an imperfect stock, and their offspring may revert 

 to their grandsire. Suppose that such reversion takes place and 

 that a fourth generation is born from this defective third genera- 

 tion, reversion is less likely to save the fourth from taint since 

 the great grandsire was unsound no less than the sire. Rever- 

 sion, in fact, is a thorough time-server, always ready to change 

 sides. In no long time the whole race will become honey- 

 combed, and what was a rare abnormality will become normal. 

 This is bound to follow, if we accept what must,! believe, be 

 recognised as facts : first, that heredity is always tending to fail, 

 and requires constantly to be maintained by Natural Selection ; 

 secondly, that not only reversion to comparatively recent forms 

 but loss, complete or almost complete, of organs or faculties is 

 not uncommon. If this is so, pammixis is great and formidable. 

 It is true that it cannot, like Natural Selection, work cumulatively, 

 adding loss to loss, as Natural Selection adds gain to gain. But 

 in one respect pammixis is in a much stronger position. It pro- 

 ceeds by much longer strides ; what has taken ages to build up 

 may be lost at one fell stroke. And the tendency to retro- 

 gression and loss being, apart from Natural Selection, the 

 dominant tendency, deficiency soon permeates the whole group, 

 when once rigorous elimination has ceased. 



The This view is not likely to find favour with those whose 

 P^ m ^ sm l ea ds them to assume that progress is the invariable 

 ol'evolu- rule in nature. If considered fairly, however, the conclusion I 

 )n have come to does not altogether run counter to such an assump- 

 tion. Natural Selection is as much part of nature as anything 

 else, and as long as it continues to act with undiminished strin- 

 gency, there is no decline from the level attained. When 

 through change of conditions its stringency is increased, there 

 is further evolution or, if we like to call it so, progress. But I 

 prefer to keep the latter word for advance in civilisation, a thing 

 quite distinct from evolution. Natural Selection, then, not only 

 makes new and higher forms of life possible, but bars the way 

 backward. It is the slackening of competition, a retreat into a 

 quiet backwater of life, that leads to retrogression. This, how- 



