BOTANY. [CHAP. i. 



broad lines has passed beyond the theory stage and is 

 proved by facts, that from a primordial type of life of 

 an exceedingly low order of development, animals and 

 plants have become gradually evolved, and that the line 

 of departure characterized by the formation of chloro- 

 phyll which enabled its respective members to feed on 

 inorganic matter, constitute collectively the Vegetable 

 Kingdom, whereas the branch that varied from the 

 primordial type in developing an internal cavity or 

 stomach for the reception of solid organic food consti- 

 tuted the starting point of departure of the Animal 

 Kingdom. 



As would be expected, the earliest groups of plants 

 and animals were but little removed structurally from 

 the parent stock, but as additional new features were 

 evolved, the differences became more marked, while in 

 the highest members the differences are so great that if 

 only the primordial type and the highest members of 

 plants and animals existed, the origin of the latter 

 from the former would probably never have been sus- 

 pected. 



For a similar reason it can be readily understood that 

 the earliest departures from the primitive types possess- 

 ing respectively plant and animal characteristics would 

 yet possess many points. in common, in fact so many 

 that even at the present day the best authorities differ 

 as to the exact plant or animal nature of numerous 

 organisms hovering round the primordial group, and in 

 which more or less visionary characters of plant and 

 animal overlap. As plant and animal characteristics 

 become more sharply pronounced and stereotyped, the 

 two divisions recede from each other to the extent of 



