226 THE THEOKY OF EVOLUTION 



showed the ' futility of the conclusions ' which are due 

 to the embryological methods. 1 ' The examples might 

 easily be multiplied tenfold/ 



According to Deperet ' this law requires to be applied 

 every time with the most extreme care. It would 

 in no case be able to dispense with the subsequent 

 proof which is provided by the actual evolutionary 

 history, i.e. by the knowledge of the palseontological 

 records/ 3 



That, in ordinary language, means that it might 

 by chance so happen, as Hackers once ' fundamental 

 law ' demands, but ordinarily it is otherwise, and in that 

 case the investigator adheres to the other cases. If, 

 despite this, the said investigators grant that earlier 

 forms in the adult condition were permanently so 

 constituted, as their present successors are only tem- 

 porarily constituted in their ' embryonic 3 or, better, 

 ' young ' stages, that is by no means surprising. 



' The palseontological Belinuridse' says, for instance, 

 Zittel in his exposition ' resemble a thousand young 

 larvae of the living (recent) " Swordtail " (Limulus) ; 

 the Pentacrinus, larvae of the Antedon, stands closer 

 to many fossil Sea Lilies than does the adult animal. 

 Certain fossil Sea Urchins retain permanently the young 

 characters ... of their still living relatives. The 

 splendid investigations of Hyatt, Wiirtenberger, and 

 Branco, have shown that all Ammonites and Ceratites 

 (Cephalopods to which the Cuttle Fish belong) pass 



1 Deperet : Umbildung der Tierwelt, p. 107. 

 i Ibid. p. 40. 



