41 



ering the whole segment but tapering below, in the upper node extending down to 

 fill the gap above the sporangium ; at c, c^ lateral tubes, in the lower node dilating 

 below, in the upper, larger above, on the right and on the left nearly obsolete ; at 

 d^ dy regular tubes from the bract. The group of three tubes arises from one brad- 

 node of the leaf. The exact development of cells at the base of this node is not 

 known ; it seems to have some peculiarties which require investigation with fresh 

 specimens. Figs. 6 and 7, nuclei with faint striae. 



Explanation of Plate xx, Ch. ^^-^/^--a-.—^A, plant natural size. Fig. i, stem and 



verticil, showing variable cortex-spines and stipules. Fig. 2, a section of the 

 stem, showing slight deviation from a regular diplostichous type. Fig. 3, two nodes 

 of a leaf, with verticillate bracts. Fig. 4, terminal node of leaf with an elongated, 

 naked, two-celled tip. Fig. 5, tip of one of the bracts (magnified 250 diameters). 

 Fig. 6, one of the mature sporangia, showing the elongated neck, and short, blunt 

 cells of the coronula. Fig. 7 and 8, mature muclei. with 15 — 16 sub-acute angles. 

 The figures (except Fig. 5) are magnified 35 diameters. 



Explanation of Plate xxi. Ch. aspera. — A, a male plant of the ordinary form 

 (from Long Island), natural size. B, a female plant of var. Macotinii, natural size. 

 Figs, 1-3, from normal form (mactoptila). Fig. I, a portion of the stem, showing 

 the irregular formation of the cortex, and the base of a verticil showing the large 

 stipules. Fig, 2, portion of a leaf bearing sporangia, with long verticillate bracts; 

 coronula somewhat divergent. Fig.- 3. portion of a leaf from the male plant. Figs. 

 4-6, from var. Macoumi. Fig. 4, stem, verticil and portion of leaf of a female 

 plant, showing small blunt spines, irregular cortex, minute stipules, minute bracts, 

 connivent coronula and the torsion of the leaf. Fig. 5, part of leaf of male plant. 

 Fig. 6, terminal node of a leaf (not always with a /z£;^-celled naked segment, but 

 often only one-celled). Fig. 7, a cluster of bulblets from the rootlets of a European 

 specimen. These consist of a simple sack filled with starch granules of varying 

 size, the largest averaging 70 /* in diameter, the interstices between the larger 

 granules being densely packed with smaller ones. Fig. 7, ^. one granule magnified 

 TOO diameters, showing a black cross with polarized light. Figures all magnified 



40 diameters. • i v n 1 *. 



Explanation of Plate xxii, Ch, fragiiis.-K plant natural size with bulblets at 

 the underground nodes. B, a verticil and leaf magnified 25 diameters; 8 and 9, and 

 ia and qa showing two terminals, the single-celled one more common. C, an en- 

 larged bulb, and a section showing numerous cells filled with starch granules. D, 

 a node beginning to deposit starch in the nodal cells. The starch seems to form 

 in the extremities of the main tubes of the stem, in the base of the leaves and in 

 the cells surrounding the base of each leaf, thus giving rise to a very complicated 

 tuber. The thickening of the tuber around the base of the leaves is well shown in 

 the magnified tuber. Fig. 10, a nucleus. 



On the Development of the Root-stock of Dicentra cucullaria. 



By Joseph Schrenk. 

 (Plate XXIII.) 



When we examine this plant in December or January, we find 

 that many of the singular bulblets of Avhich the bulk of its subterra- 

 nean portion consists, begin to push forth buds from near their bases, 

 on the inner side (toward the axis). At this time we find these buds 

 in various stages of development: some are mere protrusions above 

 the epidermis, others show plainly one or two rudimentary leaves 

 surrounded b y several scales or bracts (Plate xxni, Figs, i and 3). 1 he 

 more advanced buds have an elongated axis beset with large mem- 

 branaceous bracts, which, overlapping one another, envelop the axis. 

 In the axils of these bracts there are found miniature bulblets, either 

 singly or in clusters, shaped like the large ones from which the buds 

 have started; only at their upper end we discover a rudimentary, but 

 .very plainly tripartite leaf-blade incurved toward the axis (Fig. 



