26 LIFE ON THE EARTH. 



ceeding from such analogies to stricter inquiries, 

 other and firmer divisions were founded on the 

 organs of motion, prehension, food, respiration and 

 circulation, the organs of sense, and the internal 

 arrangements of the nervous system. In the course 

 of these inquiries we have detected, under many dis- 

 guises, some general rules of structure and function 

 patterns or types so to speak to each of which a 

 vast number of specific forms can be referred, as if 

 they were so many examples of one general structure, 

 modified in an almost infinite variety of ways to suit 

 appointed habits of life. The general characters of 

 agreement we often call typical, the special characters 

 of difference are often called adaptive terms which 

 imply the recognition of law and modification, mind 

 and choice a Creator who works by rule, and who 

 has provided for wonderful diversity in his works and 

 for the persistence through them all of some firm 

 general principles of construction, which can be 

 traced out in their operation by the human mind- 

 process of observation, comparison, and inference. 



When reduced to the smallest number of great 

 primary types, we find Plants to be ranked in two 

 divisions : 



Phanerogamous or flowering and seed-bearing, 

 and Cryptogamous or flowerless plants deficient of 

 true seeds. 



