PHANEROGAMIA : FOLIAR ORGANS. 265 



ingly exhibit in their rudimentary condition. Here careful preparation 

 and well-directed manipulation will safely admit of the measurements, 

 which must confirm the laws with complete exactness, or overturn them. 

 Moreover, the history of development alone can decide whether or not an 

 abortion has ever occurred, which expedient in particular the brothers 

 Bravais, like the whole French school since De Candolle, use rather 

 too liberally. Finally, the whole matter can only acquire especial 

 importance in botany, when we are in a condition to show, in the nature 

 of the plant, the cause why the leaves arrange themselves in a certain 

 spiral, why necessarily in this, and why they deviate therefrom under 

 certain conditions. Then will the matter first come forward as something 

 actually appertaining to the nature of the vegetable organism, since, for the 

 present, we really possess nothing but the examination of the nature 

 of the spirals in general, and the demonstration that, under certain pre- 

 suppositions, these laws found for spirals admit of confirmation in the 

 position of leaves. 



Setting aside this want of more complete scientific establishment, 

 the theory of the brothers Bravais is undoubtedly far preferable. 

 Above all, the simplicity of the law is made good, and, according 

 to a sound method, that mode of explanation is always preferred, which, 

 under equal possibilities, traces back the greatest number of cases to 

 a single point of view. Under these circumstances, perhaps, Bravais' 

 theory may even indicate how, one time or other, the regularity of the posi- 

 tion of leaves may possibly be deduced. If we recollect the well-known 

 fact, that the usually greater development of root, on account of better soil 

 on one side of a tree, also corresponds to a stronger development of the 

 annual rings and branches on this side, if we bear in mind the so fre- 

 quently isolated course of vascular bundles, which, in that case, indicate 

 the path of the influx of sap from the root to the leaves, it seems to 

 follow from this, as from a regard to what has been stated generally 

 above in reference to the independence of the vitality of the cells, that also 

 the separate perpendicular portions of the axis, lying horizontally side by 

 side, have on the whole little influence upon each other, and are tolerably 

 independent in themselves. If, then, the greatest possible number of 

 leaves be placed upon the axis, and their most uniform possible distribu- 

 tion round the whole periphery, and thence the most uniform possible 

 nutrition be effected, two leaves, one following the other, must necessarily 

 have the greatest possible, and, in relation to the circumference, irrational 

 angle of divergence, which demand the angle found by the Bravais, 

 137 30' 28", completely answers. Of course this is at present but a 

 teleological ground of explanation, but such an one may serve until a 

 better, and the true one, be found, and it may even be the index pointing 

 where to seek the truth. 



Since the buds become abortive much more readily than the leaves, and 

 often become quite displaced from their natural position by unequally rapid 

 maturation, the application which both the German and French savans 

 have made of their views to the inflorescence, seems to me to be so much 

 the less admissible, in the entire neglect of the history of development at 

 present, that it does not recommend itself by simplicity, but even deters 

 us by a rather complicated terminology. I will not by any means assert 

 that the authors have not succeeded in many instances in interpreting 

 nature correctly, but they have neglected the only possible and accurate 

 foundation the course of development ; and, therefore, there is too 

 great a danger, in accepting these doctrines, of introducing something 

 perhaps wholly false into science. 



