254 THE BIOCOSMOS PARTICULARIZED. 



through the ages, from its earliest germ to 

 the present highest form this is often called 

 its philogeny. But it has also its embryology 

 or its individual development from the germ 

 likewise to its completed growth this is 

 known as its ontogeny, which moves on a sig- 

 nificant parallel with the aforesaid philogeny. 

 The third form of vegetal evolution is the 

 ever-present total Generation of Plant-life 

 from the germ to the highest Phanerogam. 

 All three lines of the evolution of the Plant 

 move in different ways toward the common 

 end which is the Angiosperm in its supreme 

 flower. 



This brings us to the great drawback in the 

 domain of the Angiosperms : the lack of any 

 satisfactory ordering. The central difficulty 

 in our opinion pivots upon the large family 

 or tribe known as the Composite, which the 

 botanists have not been able to put into any 

 suitable place in the total Plant-world. The 

 Angiosperms aredividedprimarily into mono- 

 cotyledonous and dicotyledonous which di- 

 vision takes as its criterion the seed with its 

 embryonic leaf, which may be one or two. But 

 the seed of the Compositae (usually ranked as 

 dicotyledonous), considering the many flow- 

 ers which grow out of it in a single head, 

 should be polycotyledonous, as are the seeds 

 of certain Gymnosperms, such as the pine. 



