in tlie Reconstruction of extinct Vertebrate Forms. 491 



be, as has been shown above, either empirical or necessary. 

 Cuvier, hke a true interpictcr of nature, employed both indif- 

 ferently in his restorations, accord int;; as they were presented to 

 him, and professed it. This important fact is noivhere recog- 

 nized by Air. Huxley, who argues the case throughout as if 

 Cuvier had excluded the empirical and admitted only of neces- 

 sary correlations. He, on the other hand, denies any share to 

 the latter, and attributes the whole weight to the former. This 

 is also implied by the antithesis between " physiological cor- 

 relation or coadaptation of organs " (Cuvier), and " invariable 

 coincidence of organic peculiarities^' (Huxley). The same is 

 manifested in the references to the sculptiu-ed pollen-grains, the 

 fornas and colours of flowers, the relation between the dotted 

 vessels and naked ovula in the Gymnosperms, and the crusta- 

 cean illustration. They are all emi)irical, so far as science can 

 at present show. The special instance adduced is of the same 

 nature : " Professor Owen's determination of the famous Stones- 

 tield mammal is a striking illustration of this " (i. e. of reason- 

 ing from the law, by the logical process). "A small jaw of a 

 peculiar shape was found, containing a great number of teeth, 

 some of which were imbedded by double fangs in the jaw. Now 

 these laws have been inductively established — 



" (a.) That only Mammals have teeth imbedded in a double 

 socket {empirical). 



" [b.) That only Marsupials have teeth in so great a number 

 imbedded in so peculiarly formed a jaw {empirical). 



" By deduction from these laws to the case in question the 

 legitimate conclusion was arrived at^ that the jaw belonged to 

 a Marsupial mammal." 



Mr. Huxley has been as unhappy in this instance as with the 

 Sloth, for it so hapj)ens, that the observed characters do not 

 bear out this asserted deduction. The Stonesiield mammal par 

 excellence is the genus Amphitherium, which shows the greatest 

 number of teeth (sixteen on either side of the lower jaw), while 

 it wants the peculiar marsupial inflection of the posterior an- 

 gular process, or, at least, does not exhibit it in a greater degree 

 than the placental Mole and Hedgehog. The balance of the 

 evidence therefore " turns the scale in favour of its affinities to 

 the placental Insectivora*." On the other hand, the second 

 Stonesfield genus discovered long afterwards, Phascolotherium, 

 has fewer teeth (only twelve on either side of the lower jaw), 

 whde it does exhibit the marsupial inflection of the angular 

 process. " On reviewing, therefore, the whole of the osteological 

 evidence, it will be seen that we have every reason to presume 

 that the Amphithei-ium and Phascolothaium of Stonesfield re- 



* Owen, Brit. Foss. Mainm. p. 61. 



