llEJUVENESriENCE IN NATURE. 33 



vegetable species has its specific law in this, and some- 

 times even nearly related species are distinguished by 

 their character in this respect;* more frequently, how- 

 ever, the species of a genus, nay even the genera of a 

 family, follow essentially the same order in the production 

 of sprouts. Thus, for instance, the Grasses, Cyperacese, 

 Orchidese, Labiatse, Scrophularinese, Primulacese, Cruci- 

 ferse, Onagrese, Malvaceae, Dipsacese, and Compositse, 

 never attain the flower in the first, mostly in the second, 

 but sometimes not until the third generation ; the Plan- 

 taginese, as well as the majority of the Scitaminese, 

 Amentacese, and Leguminosse, mostly in the third ; a 

 few of the last, as Phaseolus, Apios, Hedysarum corona- 

 rium, and Trifolium montanum in the fourth. But this 

 enumeration of the essential generations of sprouts, or, 

 as they may be called, the system of axes of the plant, 

 merely marks the most general outlines of conditions 

 which include an infinite multiplicity of subordinate cases. 

 The number of the axes being equal, they divide, in the 

 first place, according to the distribution of the formations 

 on the axes in question. Especially important in this respect 

 is the behaviour of the last axis, which bears the flower. 

 Whether the last axis sets the flower immediately ,\ or 

 after the preceding formation of a definite number of 

 leaves, j or, finally, an indefinite number of leaves precede 

 the flower, § are distinctions of importance even as 

 characters of families. But also with like distribution of 

 the formations, further distinctions occur in reference to 

 the region from which the next system of the axes arises ; 

 as also, lastly, less essential ones, of great importance 

 however in regard to the habit of the plant, in respect to 



still further term in the series of generations, and the really uniaxial plants 

 are then reduced almost to none. 



* Note the genera Echium, Arabis, Sagina, Silene, Potentilla, Viola, 

 LysimaeUa, Veronica, &c. See the Ratisbon 'Flora,' 1842, 692. 



t Cyperaceae, Orchidese, Cruciferae, Balsaminese, Primulacese. 



% GramineEe and Irideae have one bract {VorhlaW) ; Labiats, Scrophu- 

 larinese, Lythrariese, and Leguminosw, have two ; Gesueriacese have three. 



§ Poleiuoniaoea;, Ligtistrineie. 



3 



