80 



in which the common fibrovascular bundles of Endogens are 

 disposed; a tendency to which is also observable in Smilax. 

 Boxhurghia I have not had an opportunity of examining. It 

 seems therefore clear that what I have elsewhere called the 

 Retose group is composed of plants whose mode of growth 

 is essentially different from that of Endogens in general ; and 

 that the species composing it stand in the same relation to 

 the mass of Endogens, as Homogens to the mass of Exogens. 

 For these reasons it appears that Endogens contain three dis- 

 tinct types of organization, namely Spermogens and Sporogens, 

 or Rhizanths, of which the former consists 1. of true Endo- 

 gens with striated inarticulated leaves, and 2. of false Endo- 

 gens with reticulated disarticulating leaves, the first of which 

 may be named Ptychogens, and the second Dictyogens. 



From these considerations we learn that of the three 

 primary divisions of the Vegetable Kingdom, recognized by 

 Jussieu, two require to be broken up into three each, and the 

 other into two ; making eight in all. The mutual relations 

 of which with each other and the Animal Kingdom may be 

 expressed thus : — 



Angiosperms. 



Homogens. Dictyogens. 



Gymnosperms. Ptychogens. 



Cormophytes. Sporogens. 



Thallophytes. 



* 



(^Animal Acrita Kingdom.) 



On the opposite page is an analytical arrangement of the 

 classes, intended to bring their distinctions more plainly 

 into view. 



