PALAEONTOLOGY AND GEOLOGY 



faith, or deductive hypothesis, which will gradually 

 be strengthened or contradicted by evidence found in 

 the structure and growth of living forms, but cannot 

 be satisfactorily established by such secondary evi- 

 dence. 



Let us imagine that none of the plants and animals 

 of past times had left any remains behind them but 

 had lived, died, and vanished or, if that supposition 

 should be too difficult, let us suppose that the re- 

 mains we find are similar to parts of existing flora 

 and fauna. Would anyone, with such a supposition 

 granted, hazard the hypothesis that life had begun 

 as a simple protoplasmic mass and had gradually 

 changed from that condition, step by step from parent 

 to offspring, until the present forms were developed ; 

 that the intermediate links had died and left us no 

 trace of their existence? 



We heard much, during the last century^ of "miss- 

 ing links" ; but we should remember, since each off- 

 spring varies from both of its parents, that the chain 

 of organic evolution, connecting two different species 

 or genera back to their common ancestor, has as many 

 links as there have been generations in both species. 

 Each ancestor, as we go back in a genealogical table, 

 is thus a link in the chain of evolution and if we think 

 of man as the descendant of the first protoplasm, the 

 number of these steps, or generations, becomes incon- 

 ceivably great. In the popular mind "the missing 

 link" has become identified with the hope of find- 



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