30 The Recapitulation Theory and Human Infancy 



living would, for the rest, afford but an unsafe basis for the 

 reconstruction of ancient faunas and floras, since experience 

 teaches that the biogenetic law is frequently veiled or completely 

 obscured owing to various causes." 



Concluding a series of illustrations of the absurdities to follow 

 from an unchecked use of the law this authority remarks that 

 these few instances "may suffice to show how trivial are the 

 discoveries concerning existence in earlier periods of earth- 

 history that can follow from ontogenetic researches alone." 48 

 Cope and others were interested in collecting particular in- 

 stances of recapitulation and these appear in the text-books. 

 They are conveniently presented by Woodward in the follow- 

 ing paragraph: 



"There is no doubt, for example, that in the course of the 

 individual development the homocercal tail of a modern bony 

 fish passes through the same stages as those successively ex- 

 hibited by the majority of the adult fishes at the different geo- 

 logical epochs. It is also evident that the family of deer (Cer- 

 vidae) has gradually acquired complex antlers in precisely the 

 same manner as every modern stag acquires them during the 

 course of its individual life. Again the "cloven foot" of the 

 existing ruminant appears in the embryo with separated meta- 

 podial bones, like those of the adult ancestral ruminants. It is 

 also tolerably certain (though fossils have not yet provided 

 absolute demonstration) that the rudimentary teeth and hind 

 limbs of the existing whale bone whales (Mystacoceti) are in- 

 herited from functionally toothed quadrupedal ancestors." 47 



In Osborn's "Evolution of Mammalian Molar Teeth" this 

 example of recapitulation is to be found, 



"In the lower molar teeth the order of calcification is precisely 



the order of evolution So we find that the order of embryonic 



development exactly repeats the order of historical development 

 .... But this .... is not exactly the case in the upper molars. 

 Nevertheless, out of eight cusps in the upper and lower molars 

 considered together, six cusps calcify in the order in which they 

 were successively added to the single reptilian cone." 48 



And from the same authority this note, 



"The recent discovery of the modes of origin of the horns in 

 the titanotheres, a perissodactyl group remotely related to 



ts Natural Science, Vol. 6, 1895: pp. 308, 309. 



47 Outlines of Vertebrate Palaeontology, 1898, p. xxiii. 



s p. 65. 



