DISCOVERIES OF CONNECTING LINKS. IO? 



with few enemies and a remarkable tenacity of life. 

 It finds its most congenial home on sand-flats, and 

 these conditions must always have existed. It is not 

 difficult, therefore, to understand that, perfectly 

 adapted to these conditions, with few enemies and 

 with great tenacity of life enabling it to endure 

 considerable changes, it has continued to exist till 

 the present day with very slight modification. It 

 is suggestive to notice that another animal which 

 exhibits a similar tenacity of life is the king- 

 crab, also an animal of very great antiquity. And 

 when with these considerations we remember that 

 all of the Silurian animals which have been pre- 

 served were marine animals, and hence living under 

 conditions which have remained practically the 

 same, we see another suggestion as to the reason 

 why this ancient fauna has continued to exist with 

 so little change. 



Recent Discoveries of Connecting Links. 



Thus far our attention has been confined ex- 

 clusively to the difficulties offered to an unhesi- 

 tating acceptance of evolution, and it must be 

 admitted that they are very great. Most of them 

 were realized by Darwin, and he attempted to cope 

 with them. And these difficulties have not grown 

 less since the appearance of the " Origin of Species," 

 but have in some respects grown greater. To ex- 

 plain, the Silurian fauna, is the greatest problem 

 which the evolutionist has to solve ; and except as it 

 has emphasized the imperfection of the record, 

 modern paleontology has not helped toward the 



