48 EVOLUTION 



person in a community," peculiarly liable to 

 go wrong and give rise to serious mischief. 

 Indeed, this is true of not a few other vestigial 

 organs. 



There is no lack of eloquent examples from 

 the animal kingdom. The baleen whale has 

 no functional teeth, and yet it has the usual 

 two sets — which never cut the gum. Whales 

 have no visible hind-legs, yet many show 

 vestiges, with bones, cartilages, and even 

 unmoving muscles, which are buried deep 

 below the surface and absolutely useless. 

 Most snakes are absolutely limbless, but in 

 the boa constrictor and some of its relatives 

 there are quite distinct hind-legs, though 

 these are so diminutive as to require looking 

 for, even on a big specimen. 



The Recapitulation Doctrine. — The 

 greatest of embryologists, von Baer (1792- 

 1876), was not an evolutionist, for reasons 

 which his dates in part explain; yet he was 

 one of the first to make clear what has always 

 been eloquently suggestive of evolution — 

 the remarkable resemblance between the 

 embryos of different types of the same great 

 group. Thus, if we take the higher Verte- 

 brates, viz. reptiles, birds and mammals, 

 there is an undeniable resemblance between 

 their embryonic stages. They seem, as it 

 were, to travel for a considerable distance 



