1856.] OWEN — STEREOGNATHUS OOLITICUS. 9 



I do not cite the other ohjections adduced in the Introductory 

 Chapter of De Blainville's " Ostc'ographie ; " because the author is 

 compelled to take away the force of most of them by excepting the very 

 bone on which the Palaeontologist would found, correlatively, his con- 

 clusions as to the subordinate structure in question ; as, for example, 

 the OS sacrum with reference to the determination whether the fossil 

 animal had or had not a tail, and the os trapezium with reference to 

 whether a fossil monkey had or had not a thumb*. 



The inapplicability of the law of correlation, as contradistinguished 

 from that of coexistence, to foreshow all the peculiarities of an ex- 

 tinct animal, is no argument against its applicability to a less amount 

 of reconstruction. 



After you have built up your Carnivore or Herbivore in a general 

 way, agreeably with the correlations so truly and beautifully followed 

 out, in either case, by Cuvier, he expressly teaches the necessity of 

 careful and close observation of those secondary coincident structures 

 by wdiich you will be able to penetrate more deeply into the affini- 

 ties, — in other words, to know more particulars of the structure — of 

 the Carnivore or Herbivore under restoration. 



The argument, therefore, against the Cu^derian rules of reconstruc- 

 tion is plainly devoid of force, which is based upon the mability to 

 reconstruct, wdien the data, e. y. the sacrum for the tail and the tru- 

 2Jezium for the thumb, are expressly excepted, whereby alone such 

 reconstruction can be completed agreeably with the Cuvierian method. 



Yet these relative shortcomings in the appliance of the principle, 

 together with the mistakes which Cuvier sometimes made, on secon- 

 dary points of affinity, in his surmises, before the requisite data for 

 comparison were at hand, continue from time to time to be cast in 

 the teeth of the disciples of Cuvier, as arguments against the prin- 

 ciples by which they believe themselves guided and sustained in their 

 endeavours to complete the glorious edifice of which their master 

 laid the foundations. 



I know no writer who more clearly defines, than Cuvier f, the limits 

 within w hich the law of correlation of animal forms may be successfully 

 and satisfactorily applied, by virtue of a knowledge of its physiological 

 condition ; or who indicates more candidly the numerous instances 

 in which — the physiological condition being unknown, and the law, 

 therefore, empirical, or one of coincidences, — careful and extended ob- 

 servation and rigorous comparison must supply the place of the more 

 direct application of the physiologically-understood law. Through 

 faith in Cuvier' s interpretation of the physiological conditions of the 

 correlations that flow from a hoof-bearing modification of the last 

 joint of the toe of an animal, I accept his conclusions as to the 

 herbivority of the extinct quadrupeds which he has called Anoplothe- 

 rium and PalcBotheriiim, and retain the conviction unshaken by any 



* "De tons les os qui entrent dans le squelette du Magot, quel est celui, sarif 

 le sacrum, d'ou Ton puisse deduire qu'il n'a pas de queue ?" p. 35. " Quel os, si 

 ce n'est le trapezdide, pourravous conduire a assurer qu'un Sapajou de la division 

 des Ateles n'a pas de pouce ?" — lb. p. 35. 



t Discours, &c. pp. 49-53. 



