FIGURE NO. 15 



EVOLUTION IN PALUDINA 



[After Neumayr] 



Here is shown a fossilized series of freshwater snails 

 belonging to the genus Paludina. The oldest form (I), 

 Paludina neumayri, is very different from the youngest 

 in this series (X), Paludina hoernesi. But the inter- 

 mediate forms (I I- IX) link them indissolubly by a 

 gradual series of transitions. The idea of evolution 

 leaps to the eye when we look at a series like this. 



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