HUGH MILLER. XXXI. 



prevalent type among fishes. Monstrosity through defect is 

 also found to increase ; so that the snake-like apoda, or feet- 

 wanting fishes, form a numerous order, some of whose genera 

 are deroid, as in the common eels and the congei-s, of only 

 the hinder limbs, while in others, as in the genera Murcena 

 and Synlranchus, both hinder and fore limbs are wanting." 

 From these and other facts our author concludes that, as in 

 existing fishes we find many more proofs of the monstrosity, 

 both from displacement and defect of parts, than in all the 

 other three classes of the vertebrata, and as these monstro- 

 sities did not appear early, but late, " the progress of the race 

 as a whole, though it still retains not a few of the higher 

 forms, has been a progress, not of development from the low 

 to the high, but of degradation from the high to the low." 

 An extreme example of the degradation of distortion super- 

 added to that of displacement may be seen in the flounder, 

 plaice, halibut, or turbot, — fishes of a family of which there is 

 no trace in the earlier periods. The creature is twisted half 

 round and laid on its side. The tail, too, is horizontal. Half 

 the features of its head are twisted to one side, and the other 

 half to the other; while its wry mouth is in keeping with its 

 squint eyes. One jaw is straight, and the other like a bow ; 

 and while one contains from four to six teeth, the other con- 

 tains from thirty to thirty Ave. 



Aided by facts like these, an ingenious theorist might, as 

 our author remarks, " get up as unexceptionable a theory of 

 degradation as of development." But however this may be, 

 the principle of degradation actually exists, and " the history 

 of its progress in creation bears directly against the assump- 

 tion that the earlier vertebrata were of a lower type than the 

 vertebrata of the same ichthyic class which exist now." 



[n his next and tenth chapter, our author controverts, with 

 liiis usual power, the argument in favour of the development 

 hypothesis drawn from the predominance of the brachiopods 



