28 Darwinism and Other Essays. 



birds, able to fly back and forth over the inter- 

 vening sea. Unless the Darwinian theory be 

 true, these striking relations not only become 

 meaningless, but it is difficult to see why any 

 discernible relations at all should exist between 

 these neighboring faunas. To cite all the con- 

 firmatory facts of this sort would be to write an 

 exhaustive account of the distribution of plants 

 and animals. 



In examining the geological record in general, 

 we are struck with its corroboration of the above- 

 cited testimony of classification and embryology. 

 For instance, as we go back in time, we find fam- 

 ilies and orders drawing more and more closely 

 together; we find earlier forms less specialized 

 than their successors ; and, as we now have em- 

 bryonic birds with rudimentary teeth in their 

 beaks, so we find that formerly adult birds with 

 such teeth existed. It is one of the most signifi- 

 cant truths of palaeontology that extinct forms are 

 generally intercalary between forms now existing ; 

 so that not only genera and families, but even 

 orders, of contemporary animals are every now 

 and then fused together by the discovery of ex- 

 tinct intermediate forms. It is in this way that, 

 the Cuvierian orders of pachyderms and rumi- 

 nants have come to be ranked as a single order, 



