VARIATION IN TIME 155 



perfect degree, in the most diverse representatives 

 of nearly all orders of Mammals ? 



These examples, which it would be easy to multi- 

 ply as regards other groups of fossil animals, will 

 suffice to explain why modern palaeontologists have 

 abandoned these approximative methods, which 

 lead, almost fatally, to a fantastical evolution. 

 Perhaps these crude theories may not have been 

 useless in the past, when there was a struggle to 

 bring about the acceptance of evolutionary ideas ; 

 but they are now unfavourable to progress by 

 fostering illusions as to the real state of advance- 

 ment of our science. The time has come when 

 palceontological evolution should be the history of 

 what has really taken place, and not a poetic 

 image of what might have occurred in early 

 times. 



Let us now return to a more scientific method, 

 of which the essential theme is the exact and minute 

 reconstitution of the real branches which represent 

 the direct genealogy of our animal forms. The 

 inception and merit of this must be accorded to the 

 remarkable researches of the Austrian palaeonto- 

 logists on the Formenreihe, literally the series of 

 forms a term which I prefer to render by the 

 more expressive name of phyletic branches. The 

 process of reconstruction of these series, simple 

 as it is in theory at any rate, consists in following 

 step by step in a succession of regularly superposed 

 and continuous geological strata, the chronological 

 variations of the same type or of types sufficiently 

 linked together by their natural affinities for their 

 genealogical relations to force themselves upon any 



