NATURAL HISTORY OF CREATION. 169 



Dr. Fletcher's scale, it may be remarked, was not made 

 up with a view to support such an hypothesis as tlie 

 present, nor with any apparent regard to the history of 

 fossils, but merely to express the appearance of advance- 

 ment in the orders of the Cuvierian system, assuming, as 

 the criterion of that adv^ancement, '^ an increase in the 

 number and extent of the manifestations of life, or of 

 the relations which an organised being bears to the 

 external woi-ld." Excepting in the relative situation of 

 the annelida and a few of the mammal orders, the parity 



osseous fish ; at the third, that of a turtle ; at the fourth, that of a 

 bird ; at the fifth, that of one of the rodentia ; at the sixth, tliat 

 of one of the ruminautia ; at the seventh, that of one of the digitigrada; 

 at the eighth, that of one of the quadrumana ; till at length, at the 

 ninth, it compasses the brain of Man ! It is hardly necessary to saj, 

 that all this is only an approximation to the truth ; since neither is 

 the brain of all osseous fishes, of all turtles, of all birds, nor of all the 

 species of any one of the above order of mammals, by any means 

 precisely the same, nor does the brain of the human fatus at any 

 time precisely resemble, perhaps, that of any individual whatever 

 among the lower animals. Nevertheless, it may be said to represent, 

 at each of the above-mentioned periods, the aggregate, as it were, 

 of the brains of each of the tribes stated; consisting as it does about 

 the second month, chiefly of the mesial parts of the cerebellum, the 

 corpora quadrigemina, thalami optici, rudiments of the hemispheres 

 of the cerebrum and corpora striata ; and receiving in succession, at 

 the third, the rudiments of the lobes of the cerebrum ; at the fourth, 

 those of the fornix, corpus callosum, and septum lucidum ; at the 

 fipLh, the tuber annulare, and so forth ; the posterior lobes of the 

 cerebrum increasing from before to behind, so as to cover the thalami 

 optici about the fourth month, the corpora quadrigemina about the 

 sixth, and the cerebellum about the sc^venth. This, then, is another 

 example of an increase in the complexity of an organ succeeding its 

 centralisation ; as if Nature, having first piled up her materials in 

 one spot, delighted afterwards to employ her abundance, not so much 

 in enlarging old parts as in forming new ones upon the old foundations, 

 and thus adding to the complexity of a fabric, the rudimental structure 

 of which is in all animals equally simple. " — Fletcher's " Eudiments of 

 Physiology." 



