THE ARCHIPELAGO OF BREHAT. 93 



the physiologist, who attempts to penetrate into the 

 inmost recesses of their structure for the purpose of 

 studying their modes of action, will often find that 

 the simpler types of animal life furnish us with 

 numerous data for the elucidation of many of 

 the problems which nature has presented to us, 

 although these data may have been unsuccessfully 

 sought for in beings of higher development. An in- 

 timate acquaintance with these classes, which have 

 hitherto been too much neglected, is equally necessary 

 to the zoologist who, with a just appreciation of what 

 is due to the character of his science, avails himself 

 of the light afforded by anatomy and physiology, 

 while he does not neglect the study of the relations 

 by which living beings are connected together. I 

 will, however, somewhat more fully develop my 

 views of this subject. 



When, after the first attempts to classify animal 

 species, naturalists arrived at some general ideas, the 

 fact of the relative superiority and inferiority of the 

 animals which they studied must have been one of 

 the first things which struck them. At the one ex- 

 tremity of the chain of comparison stood a portion of 

 the Mammalia, at the other appeared the Worms and 

 Zoophytes. The numerous intermediate forms pre- 

 senting themselves between these extreme limits gave 

 rise to the idea of an uninterrupted animal series, ex- 

 tending through a succession of progressive degrada- 

 tions, from man, who comprehends and controls 

 nature by his intelligence and perfect organisation, 

 down to the sponge, which appears from its am- 

 biguous structure to be equally referrible to either 



