140 THE EVOLUTION OF LIVING BEINGS. 



re for the degree of relationship, optimistic natures 

 could continue to believe that arrangement of the 

 different types according to their degree of similarity, 

 would give a picture — be it a blurred one — of phy- 

 logeny. 



Now we know that similarity, neither phenotypical 

 nor genotypical similarity, is a criterium for relation- 

 ship. 



Sisters can be more dissimilar than two girls of quite 

 different extraction, and consequently similarity gives 

 us no measure whatever of relationship. 



And as we know furthermore, that crossing has oc- 

 curred and does occur daily, that it produces many dif- 

 ferent types, from which but a few survive, after having 

 recrossed in alle directions, we know that evolution 

 proceeds forwards, sidewards and backwards, along 

 the meshes of a net, so that it is absolutely hopeless to 

 choose out of the many ways, in which one can draw 

 a broken line on such a netting, the one along which 

 evolution has proceeded. 



Phytogeny e. g. reconstruction of what has happened in 

 7 the past, is no science but a product of phantastic specu- 

 lations which can be held but little in check by the geo- 

 logical record, on account of the incompleteness of the lat- 

 ter. 



Those, who know that I have spent a considerable 

 part of my life in efforts to trace the phylogeny of the 

 vegetable kingdom, will know, that this is not writ- 

 ten down lightly; nobody cares to destroy his own 

 efforts. 



Every author, who cares to be taken as a man of 



