2 INTRODUCTION TO CRYPTOGAMIC BOTANY. 



with Liliitm* Attentive study will soon prove the two 

 grand divisions above-named of Exogens and Endogens to 

 be founded in nature, as far as any divisions can be shown 

 to be so, by their mode of germination, the law of increase 

 in their stems, and the venation of their leaves ; and so in the 

 minor groups, though there will be many a preconception to 

 overthrow, still structure will as before confirm the indications 

 of outward form, except, as said above, where such indications 

 are mere matters of external resemblance, apart from every 

 essential character. 



2. The eye, however, will have already distinguished a third 

 grand class,f more distinctly indicated perhaps even than the 

 other two, though composed of parts still more widely differing 

 from each other. It will have seen the rocks and trees covered 

 with pigmy forms of vegetation, often displaying nothing Hke 

 a leaf, or the pecuHar green tint of the vegetable world ; or 

 if something approaching to a stem and leafy appendages 

 be present, so cramped, attenuated and filmy, at once so 

 easily dried up by heat, and capable of being restored by 

 moisture, as to present something at once distinguishable 

 from ordinary vegetation. 



The waters, whether fresh or salt, meanwhUe teem with 

 other vegetable organisms, distinguishable at once from the 

 mere aquatic Phaenogams amongst which they grow, and 



* After a patient examination of germinating plants, and an atten- 

 tive consideration of the whole question, I cannot but subscribe to the 

 view which considers Nymplima as a true Exogen, notwithstanding 

 some anomalies of structure in the common stem, and the peculiarities 

 of the seed. Nor, again, can I subscribe to that view which would 

 place Nelumhium and Nymphcea in diiFerent divisions, though, if that 

 were correct, no better example could be adduced in illustration of the 

 text. 



t I cannot consider Dictyogens (much less Rhizogens and Gymno- 

 gens) as a class of the same importance with Endogens and Exogens. 

 They are so clearly Endogenous, notwithstanding the peculiarities of the 

 venation or much more of the structure of the stem, which may be easily 

 studied by English botanists in Tamus, that, unless every anomaly is 

 to be considered as overthrowing a natural division, we must either 

 be content to leave them in company with their allies, or give up the 

 attempt of natural arrangement altogether. 



