48 



4, bb., and Fig. 5). This rudimentary blade attains a greater size 



and development on those bulblets that grow at the top of the axis. 



In every vigorous shoot we find, near the end of the axis, one, or 



often two leaves which are so far advanced in growth that the entire 



Dicent 



They 



even have a greenish tinge, although closely wrapped up by the bud- 

 scales and growing under ground. But besides having an almost 

 fully developed lamina, such perfect leaves are remarkably different 

 m regard to their petioles from the ones with only rudimentary blades. 

 With these, the bulblet itself is simply a greatly enlarged, roundish- 

 triangular leaf-stalk, bearing at its top a mere vestige of a lamina, while 

 the_ well-developed blade of the former is borne on an elongated, 

 typical petiole, which only at its very base presents an evidewt, though 

 comparatively slight swelling (Fig. ij, pt. and Fig. 6, «.) At the 

 flowering time (in April), when the leaf- blades have fully ex- 

 panded this slight swelling of the petiole-bases has increased 

 enormously (Fig. 7.); and when in summer the foliage has withered 

 away, these enlarged petiole-bases persist and help to form the 

 singular subterranean stem of our plant. They then remotely 

 resemble beech-nuts in size and shape, but the edges are not so sharp, 

 and the inner side is flat. We can easily recognize them by the 

 triangular, dark brown scar left at the top where the thinner part of 

 the petiole has withered away. 



The minute bulblets, which I mentioned above as growing in the 

 axils of the bracts on the elongating axis, do not develop their rudi- 

 mentary leaf-blades at all, but soon lose nearly every trace of them, 

 retaining only a small incurved point at the top_ But their mass 

 increases very considerably, while the axis to which they belong, and 

 at the top of which the real leaves are growing, does not lengthen in 

 proportion, so that at the end of the growing season these bulblets 

 are lound crowded under and around the large persisting petiole-bases 

 described above. Their outer sides are not concave, but rather 

 convex (Fig. 2), and in size they vary very much, some being 

 as ^ small as millet or hemp seeds, while others are as large as 

 grains of wheat or even of corn. They have of course no scar at the 

 *K^' ^J^j^^'^i^l ^^^de of their early stage of development having been 

 absorbed or transformed into a smooth blunt point. 



On the ground of these observations we might distinguish two sorts 

 of 'granulate bulblets" growing on the root-stock of Dicentra 

 cucuUaria, viz., ist, metamorphosed petiole-bases, and 2nd, abortive 

 leaves. Their physiological functions are, no doubt, identical; and, 

 in regard to structure and contents, there is not much essential dif- 

 ference; the bulblets of both kinds contain numerous fibro-vascular 

 bundles scattered through the bulk of large parenchymatic cells that 

 are crowded with starch-granules; but in bulblets of the first kind 

 ^\1 T ^'^^ ,'m' '? ^'' '^'^"^S principal fibro-vascular bundles 

 kiml (Flg"t) ' ' ^'' ""^ ''''^' ^^'^' ^^ *^°'^ ""^ ^'^^ ^^^°^d 



Every one of these bulblets is provided at its base with a bud 



a't the s'^me tim J P"'"'"-'' "'" "^^^ ^^^^"S ^^^ -^^ — > -Me! 

 at the same time, new axiai organs spring from the main stem. It is, 



