344 DISCOURSE ON THE STUDY 



marks, but not such as will long detain the reader's 

 attention. 



(381.) In zoology, the connection of peculiar modes 

 of life and food, with peculiarities of structure, has 

 given rise to systems of classification at once ob- 

 vious and natural ; and the great progress which 

 has been made in comparative anatomy has enabled 

 us to trace a graduated scale of organization almost 

 through the whole chain of animal being ; a scale 

 not without its intervals, but which every successive 

 discovery of animals heretofore, unknown has tended 

 to fill up. The wonders disclosed by microscopic 

 observation have opened to us a new world, in 

 which we discover, with astonishment, the extremes 

 of minuteness and complexity of structure united ; 

 while, on the other hand, the examination of the 

 fossil remains of a former state of creation has 

 demonstrated the existence of animals far surpassing 

 in magnitude those now living, and brought to light 

 many forms of being which have nothing analogous 

 to them at present, and many others which afford 

 important connecting links between existing genera. 

 And, on the other hand, the researches of the com- 

 parative anatomist and conchologist have thrown 

 the greatest light on the studies of the geologist, 

 and enabled him to discern, through the obscure 

 medium of a few relics, scattered here and there 

 through a stratum, circumstances connected with 

 the formation of the stratum itself which he could 

 have recognised by no other indication. This is one 

 among many striking instances of the unexpected 

 lights which sciences, however apparently remote, 

 may throw upon each other. 



