170 THE NATURAL SYSTEM. 



New Holland in 1810 ; and finally Do Candolle, by the publication of his great 

 work " Prodromus Systematis Naturalia Regni Yegetabilis", commenced in 181G, 

 and designed as the universal Flora, brought this system into general use. 



832. Many systems. But the aim of the natural system a3 an expression oftho 

 Divine Order of Nature i3 not yet consummated. The lower divisions of the System 

 — species, genera, and orders, — are well defined and settled as truly natural groups. 

 The grand divisions also, — Cryptogamia, Phenogamous Exogens and Endogens 

 (§ 897). — are fully established. But in the midst, between these extremes, there is 

 a region of uncertainty, respecting the arrangement of the orders into groups sub- 

 ordinate to the grand divisions, viz., into Classes and Subclasses. In this matter, 

 authors have maintained different views, and proposed a variety of systems. 



893. The difficulty lies in this. \7o attempt necessarily a linear arrangement 

 ©f the orders, placing one after another in succession, thus regarding the affinities ot 

 each in two directions only, viz., toward the preceding and the succeeding ; whereas 

 each order should be regarded as i center of affinities; being related immediately to 

 all others lying around it, as a province on a geographical map is related equally to 

 all those which touch upon its borders. Hence any linear arrangement of the ordera 

 must be in some degreo artificial: 



894. One natural system. Although there be but ono truly na- 

 tural system, yet while any portion of it remains imperfectly understood, 

 so far authors may be expected to hold different views, and to attempt 

 by different methods to express that true system. Still the discrepan- 

 cies observed in the several "Natural Systems," proposed by different 

 writers, are slight compared with the number and importance of the 

 principles now common to them all and universally admitted. 



895. The first and highest division of the Vegetable Kingdom, 

 viz., into the Phsenogamia or Flowering Plants, and the Cryptogamia 

 or Flowerless Plants, has already been noticed and defined. These 

 grand divisions, or sub-kingdoms, lie at the foundation of both the sys- 

 tems of Linnaeus and of Jussieu, and have in substance been adopted by 

 every subsequent author. It is a division founded in nature, that is, 

 marked by nature herself, for 



The Phaenogamia (<j>aivu, to appear, yu/ior, nuptials), 



a, Consist of a regular axis of growth with leafy appendages, 



b, They possess a woody and spiro-vascular structure, 



c, They develop stamens and pistils constituting flowers. 



d, They produce seeds containing an embryo. On the other hand 

 Tho Cryptogamia (Kpvw-u, to conceal, yujio^). 



a, Are generally destitute of a regular axis and of true leaves, 



b, They possess mostly a cellular structure only, 



c, They do not develop true flowers, 



d, They produce spores having no embryo. 



896. Natural divisions indefinite. The above diagnosis does not mark the 

 absolute limits between the two sub-kingdoms, for the higher Cryptogamia. as tho 

 mosses and ferns, give indications of approach to the Plnenogamia, both in form and 

 structure, while tho lower Phajnogamia can scarcely be said to produce flowers. 

 And universally, so gradual is the transition from group to group, that it is difficult 



