Likenesses; or, Philosophical Anatomy 265 



I Now, we contend that it is against reason to suppose that 

 ere indefinite variation, together with the ' survival of the 

 fittest,' could ever have built up all these serial, lateral, and 

 other homologies without the action of some innate power or 

 tendency so to build up, possessed by the organism itself 

 in each case. 



AVhat can be more wonderful than the symmetry of those 

 lowly but beautiful organisms, the Acanthomeirce, a S3rm- 

 nictry for which it is difficult to conceive any external cause ? 



Hardly, if at all less wonderful, is the radial symmetry of 

 the Echinoderms (the sea-stars, sea-eggs, and sea-urchins) 

 Avith their multitudinous variety of component parts. If, 

 then, internal forces can build up such varied structures 

 as these, they may well be also capable of producing the 

 various serial, lateral, and vertical S3rmmetries which higher 

 animals exhibit. 



We may next consider whether there are not other 

 external evidences (besides the homologies themselves) of 

 the existence of such an internal power, by the action of 

 which these recondite 'likenesses' may be conceived to 

 be brought about. It is here contended that there is good 

 evidence of the existence of some such special internal power, 

 which evidence may be gathered from three sources: 1, 

 Comparative anatomy; 2, the science of monstrous births, 

 or teratology; and 3, the science of diseased structures, 

 or pathology. 



First, as to comparative anatomy, one example may 

 be selected where others can be easily adduced, if required.^ 



On the hypothesis of evolution, tortoises must be reckoned 

 as very far indeed from being the first and earliest kinds of 

 (juadrupeds. Yet certain tortoises exhibit the most extra- 

 ordinary resemblance and correspondence between their 

 iinterior and posterior Hmbs. This degree of likeness and 



^ For others see Genesis of Species, chap. viii. 



