120 THE PHBNOMKNON OF 



distribution in plants, their transitions and alternations, 

 and all this can only be afforded by a more or less per- 

 fectly-developed condition of the plant. A sufficiently 

 large number of le*aves must have been formed before we 

 can safely judge of their arrangement, since a measure- 

 ment of the divergence of the earliest rudiments of the 

 leaves is as impracticable as every later direct measure- 

 ment. Hence the investigation of the earliest rudiments 

 in reference to this point will be of little use until the 

 condition of arrangement of the full-grown plant is known. 

 Even those conditions frequently coming with the com- 

 pletion of the development, disturbing the original 

 arrangement, as for example, the unilateral pushing together 

 of the leaves when there is unequal thickening of the 

 sides of the stem, the moving back of leaves by unequal 

 adhesion of the base, the apparent change of the arrange- 

 ment of the leaves from revolution of the stem, &c., 

 require no great research into the rudimentary structure 

 to set them aside. Thus the method of determination 

 may be perfected, without directly tracing the first origin 

 of the leaves, to such a degree that the modes of arrange- 

 ment are almost everywhere to be arrived at, and a com- 

 parative investigation, carried out properly by means of the 

 method we possess, is capable of bringing Phyllotaxy to 

 such results, that it makes each individual case compre- 

 hensible in orderly connection with the entire system of 

 the arrangements of leaves. The true side of Schleiden's 

 objection is, that this is not the final result, the final 

 establishment of Phyllotaxy, since for its completion we 

 necessarily require the elucidation of the connection of the 

 external arrangement of the leaves with the internal 

 arrangement of the cells in the apex of the stem, from 

 which the leaves emerge, and in which, simultaneously 

 with their origin, is laid the foundation of their 

 arrangement, — a problem toward the difficult solution of 

 which, the study of development has not yet made the 

 slightest step, at least in the realm of the Phanerogamia ; 

 moreover thiis also includes the explanation of the organic 



