Dr. Lindlcifs Natural System of Botany. 295 



ley, the Equisetaceas,) and the Rhizanthce, as originally established 

 by Blutne, being here admitted to the rank of independent classes. 

 Their claim to this rank, however, can as yet be hardly considered 

 as fully established. 



" One of the first things that strikes an enquirer into the structure 

 of plants, is the singular fact, that while all species are capable of 

 propagating their race, the mode in which this important function is 

 accomplished is essentially different in different cases. The great 

 mass of plants produce flowers which are succeeded by fruits, con- 

 taining seed, which is shed or scattered abroad, and grows into new 

 individuals. But in Ferns, Mosses, Mushrooms, and the like, nei- 

 ther flowers, nor seeds properly so called, can be detected ; but pro- 

 pagation is effected by the dispersion of grains or spores which are 

 usually generated in the substance of the plant, and seem to have 

 little analogy with true seeds. Hence the vegetable world separates 

 into two distinct groups, the Flowering and the Flowerless. Upon 

 examining more closely into the respective peculiarities of these 

 two groups, it is found that flowering plants have sexes, while flow- 

 erless plants have none; hence the former are called Sexual, and the 

 latter Asexual. Then again the former usually possess a highly de- 

 veloped system of spiral or other vessels, while the latter are either 

 altogether destitute of them, or have them only in the highest orders, 

 and then in a peculiar state : for this reason flowering plants are also 

 called Vascular, and flowerless Cellular. More than this, all flower- 

 ing plants, when they form stems, increase by an extension of their 

 ends and a distention or enlargement of their sides ; but flowerless 

 plants appear to form their stems simply by the addition of new 

 matter to their points ; for this reason while the former are princi- 

 pally Exogens or Endogens, the latter are called Acrogens. Flow- 

 ering plants are also for the most part furnished with respiratory or- 

 gans or stomates, while flowerless plants are to a great extent desti- 

 tute of them. No one then can doubt that in the vegetable king- 

 dom, two most essentially distinct divisions exist, the Flowering and 

 the Flowerless, and that these differ not in one circumstance only, 

 but are most essentially unlike in many points both of organization 

 and physiology. 



" In like manner. Flowering plants are themselves divisible into 

 equally well marked groups. Some of them grow by the addition 

 of new woody matter to the outside of their stem beneath the bark ; 

 these are Exogens : others grow by the addition of new woody mat- 



