REJUVENESCENCE IN NATURE. 39 



above or below the earth, with or without tuberous struc- 

 tures, spine- branches,* &c., are characteristic of particular 

 species of plants. Thus, in spite of the distinction between 

 essential and inessential sprouts, we must acknowledge, 

 that from a higher point of view all sprouts appear es- 

 sential. As it is not merely in the last stages of the 

 metamorphoses that the life reveals its peculiarities, 

 since every one of the lower stages also turns outwards 

 a special side of the living essence, not only are those 

 sprouts which bear relation to the attainment of the goal 

 of the metamorphosis to be called essential, but also, 

 everything else in the collective circle of those structures 

 which are destined to represent the plant on all sides, and 

 can not be removed from that circle without essential interfe- 

 rence with the characterisation of the plant. A fewexamples 

 may render more clear the importance of the inessential 

 or repetition-sprouts in the characterisation of the plant. 

 The peculiar forms of the crowns of trees, for instance 

 of the pyramidal poplar, of the cypress, depend upon the 

 proportion of the vigour and abundance of the repetition- 

 sprouts to the main sprout or trunk of the tree. The 

 relation of arrangement shows itself more distinctly in 

 many Conifers, where the repetition-sprouts over-leap 

 certain tracts which remain without branches, and form 

 tolerably regular whorls. In Pinus the tracts between 

 the larger, whorled branches are occupied by the small 

 (essential) leafy branchlets. Essential and inessential 

 sprouts occur in extremely regular alternation in Tro- 

 p&olum minus, when every third flower-sprout is followed 

 by a euphyllary leaf sprout. When there is | arrange- 

 ment of the leaves on the main-shoot, the euphyllary leaf 

 sprouts derive from this an arrangement according to 

 f- in the reverse direction. Here also may be mentioned 

 the peculiar cases where the leaves having a many-ranked 

 direction, the branches are nevertheless in distichous 

 arrangement, on account of only part of the leaves pro- 



* See Pi-unus, Pi/run, Crateffus, Rhumnus. 



