in the Reconstruction of extinct Vertebrate Forms. 493 



Througliout Mr. Huxley's brochure there runs a strain of 

 extolment of what is empirical in natural history at the expense 

 of the rational. Let him be the great expounder of its aesthetics, 

 if he likes, — every one will cheer him on. But he must beware 

 of attempting to put back the hand of the rational dial, for 

 every arm will be against him. The circulation of the blood 

 has been stoutly denied in Britain within the memory of thou- 

 sands now living. Strange events of this kind make their 

 appearance periodically in all the sciences. They are anachron- 

 isms, which startle by their unexpectedness, and then pass into 

 oblivion. How different were the aspirations of Cuvier ! " Avec 

 cette derniere precaution,^' {i. e. le habitude de ne se rendre 

 qu'h ^evidence, ou du moins de classer les propositions d'apres 

 le degre de leur probabilite) '^ il n'est aucune science que ne 

 puisse devenir presque geometrique : les chimistes Pont prouve 

 dans ces derniers temps pour la leur ; et j'espere, que Fepoque 

 n'est pas eloignee ou. Ton en dira autant des anatomistes.'' 



One other remark is necessary. Although the principle of 

 correlation is borne out by a cumulative mass of evidence that is 

 irresistible, it must not, in practice, be pushed too far in palae- 

 ontology. There are numerous instances on record, in which, 

 in attempting to determine extinct forms from a single bone or 

 tooth, or from imperfect materials, very erroneous conclusions 

 have been arrived at; among others, even by Cuvier himself. 

 And since his time, the same lower jaw, presenting nearly the 

 whole series of teeth, has been referred, by different eminent 

 comparative anatomists, to a fish, a reptile, and a mammal ! 

 When these cases are examined under the light of improved 

 knowledge, they furnish no grounds to weaken our confidence 

 in the constancy of the zoological laws of correlation ; but an 

 emphatic warning to interpret the evidence carefully, leaving no 

 part of it out, and to eschew Hasty conclusions where it is 

 inadequate. 



De Blainville, smarting under the sting of some signal mis- 

 interpretations committed by himself, unceasingly inveighed 

 against the sufficiency of a single fossil bone for the reconstruc- 

 tion of the form. At the present day, some molar teeth of a 

 fossil mammifer have been met with in the Trias of Stuttgart. 

 The cast of one of them has been shown to one of the most 

 competent living authorities, who, it is stated, " is not able to 

 recognize its affinity with any mammalian type, recent or extinct, 

 known to him.'' But when Mia^olestes antiquus is better 

 known, upon more copious materials, we may have everj con- 

 fidence, judging from past experience, that its teeth will be 

 found to be in perfect harmony with the rest of its organization, 

 and amenable to the laws of zoological correlation. 



