THE RECAPITULATION THEORY 303 



Theory, does in reality exist. There is much yet 

 to be done in this direction. A commencement, a 

 most promising commencement, has been made, 

 but as yet only a few groups have been seriously 

 studied from this standpoint. 



It is a great misfortune that palaeontology is not 

 more generally and more seriously studied by men 

 versed in embryology, and that those who have so 

 greatly advanced our knowledge of the early 

 development of animals should so seldom have 

 tested their conclusions as to the affinities of the 

 groups they are concerned with by direct reference 

 to the ancestors themselves, as known to us 

 through their fossil remains. I cannot but feel 

 that for instance the determination of the affinities 

 of fossil Mammalia, of which such an extraordinary 

 number and variety of forms are now known to us, 

 would be greatly facilitated by a thorough and 

 exact knowledge of the development, and especially 

 the later development, of the skeleton in their 

 existing descendants, and I regard it as a reproach 

 that such exact descriptions of the later stages of 

 development should not exist even in the case of 

 our commonest domestic animals. 



The pedigree of the horse has attracted great 

 attention and has been worked at most assiduously, 

 and we are now, largely owing to the labours of 

 American palaeontologists, able to refer to a series 

 of fossil forms commencing in the lowest Eocene 

 beds, and extending upwards to the most recent 

 deposits, which show a complete gradation from a 

 more generalised mammalian type to the highly 



