100 CLASSIFICATION OF AMPHIBIAXS. 



mediate between reptiles and fish^ it becomes absolutely 

 necessary that such animals should exhibit differences 

 from both the classes they are intended to connect ; that 

 they should be^ in fact, the graduating links — the nar- 

 row but well-proportioned passage— which is to lead 

 us from one vestibule of nature's temple to another ; 

 and so, accordingly, do we find them. So far, then, is 

 the siren from being peculiarly formed, so to speak, for 

 setting natural classification at defiance, that it offers 

 one of the most beautiful and most essential hnks in the 

 chain of nature. The anomaly would be, if such ani- 

 mals had never been created. Without them there 

 would be a gap, '' which nature's self would rue," as 

 destroying, in the most perfectly-organised kingdom of 

 the animal world, that particular race of beings which 

 demonstrates the union of the whole of the vertebrated 

 animals into one vast circle. 



CHAP. VIII. 



(lO-t.) The class of reptiles, which we now enter upon, 

 comprehends a large but uninviting assem.blage of ani- 

 mals, wherein the vertebrated structure, in some groups, is 

 reduced to its minimum. The form, indeed, which nature 

 has now assumed, is associated, in most minds, with de- 

 formity or with horror. Yet, however the bulk of man- 

 kind may turn with disgust from the contemplation of 

 these creatures, the philosophic observer, who knows 

 that every thing which has proceeded from the hand of 

 Omnipotence is, in its kind, good and perfect, will 

 patiently investigate their history, and will endeavour to 

 illustrate, in these despised and repulsive animals, those 

 sublime truths of unity of plan which are as perfect 



