70 THE PHENOMENON OF 



involucre and involucel exhibit scarcely^ -^ breadth of 

 the base. 



Mahonia Aquifolium. The cataphyllary leaves (bud- 

 scales) are about embracing; the euphyllary leaves 

 falling to or i ; the hypsophyllary leaves on the axis of 

 the panicle \ ; the little bracteoles (vorbldtter] occurring 

 on the stalk of the flower itself, which, however, rarely 

 come to evident development, are still narrower than the 

 bracts (deck-blatter) of the inflorescence. 



Thus the plant, as a general rule, exhibits the phe- 

 nomenon of decrease in regard to the breadth of the base 

 of the leaf, yet with two retrogressions (inconsiderable, 

 however), namely, at the commencement of the flower, and 

 again at the close of series, in the formation of the fruit. 

 The following remarks will show that this decrease in the 

 breadth of the base of the leaf does not in itself indicate 

 any decrease in the energy of the leaf-formation, but that, 

 on the contrary, the expansion of the base stands in an 

 antagonistic relation to the development of the middle of 

 the leaf. 



The development of the leaf in length or height, which 

 is the most influential factor in reference to the size of 

 the leaf generally, and the vigour which declares itself in 

 its formation, exhibits, in the progressive metamorphosis 

 of the plant, a totally different course from that of the 

 breadth of the base. Both in the first and second regions, 

 on the " stock" and in the flower, the longitudinal deve- 

 lopment of the leaf shows, first an increase and then a 

 decrease; the commencement of the last region, the 

 fruit, is connected with another increase. Thus after a 

 double rise and fall the terminal formation is attained in 

 a third ascent. Reviewing first of all the first region, 

 we find that the first cataphyllary-leaves of a sprout are 

 always the shortest and smallest; this rule prevails, in 

 like manner, in the first euphyllary-leaves of plants, or in 

 individual sprouts of plants where the cataphyllary leaf- 

 formation is wanting. The cotyledonary commencement 

 often forms an exception in this respect, as in reference 



