138 TRANS. OF THE ACAD. OF SCIENCS. 



shortened and thickened internodes or joints a large quantity of starch aa 

 food for the young plants, which in the succeeding season spring from 

 the terminal bud at the tip and the axillary bud at the base of the tuber. 

 These tubers are 5-10 inches long, 1-2 inches in diameter, somewhat 

 spindle shaped, depressed, and not rarely angled and furrowed, and 

 weigh 2-8 ounces ; they are traversed by the same system of tubes as the 

 summer stems ; the tubes, however, are mostly of a more irregular shape 

 and more or less compressed. Our plant having no truly perennial root- 

 stock like its relatives, the Nymphceucetz, the tubers and their buds are the 

 only parts which live through winter, much like those of the potatoe. 



Leaves.— All the foliaceous organs, with the exception of those in the 

 flower proper, are either distichously alternate, or they are superimposed 

 in the order detailed above. The lowest scale, a, is about 3 inches long 

 and envelops the whole bud ; the growing stem, enveloped by the stipule, 

 bursts through its very thin back, while the leaf and the flower-bud, wrap- 

 ped in the second scale, b, pass out on the upper, open side, leaving its 

 upper part, when entire, between the leaf and the stipule ; at last, it usu- 

 ally divides into two halves, with lateral positions. 



The second scale, b, is 3-5 or sometimes even 6-8 inches long, bears in 

 its axil always the flower-bud, and originally envelops that and the leaf, 

 but not the stipule; it remains on the back of the peduncle, or, where 

 that remains undeveloped, of the petiole. 



The peltate, orbicular leaf, C, has often been described. T allude here 

 only to the 6 tubes of its stalk, arranged exactly as in the smallest branch- 

 es, the smallest pair on its posterior, grooved side. The epidermis-cells 

 of the upper surface are very small (0.007-0.010 lines diameter) and an- 

 gular, each with a little knob, which' together produce the velvety, water- 

 repelling surface ; the lower surface is formed of a single layer of much 

 larger cells (0.020-0.025 lines) with tortuous walls, and is kept distended 

 and separate from the parenchym of the leaf by a kind of framework 

 built of cells, which forms a network of meshes filled with air. Only the 

 upper surface ha? stomata. At the base of the leaf a stipule, in shape 

 and texture similar to the scales, in full sized specimens 2-2£ inches long, 

 envelops the axillary bud as well as the continuation of the stem ; while 

 the latter, growing out, leaves it on its upper side, the branch pene- 

 trates its back, thus placing it between itself and the stem, or at last splits 

 it in two. 



The first opposite leaves of the flowering branch may be classed as 

 bracts ; from the very similar exterior sepals, they may be distinguished 

 by their position, smaller siz<>, and persistency ; they are already observed 

 in the smallest bud, of 0.1 line diameter. The succeeding organs of the 

 flower are arranged in much more complicated phyllotactic orders. 



The lowest, superimposed scales of the leaf-branch are close between 

 the branch and the stem; the lowest one is only 6 9 lines long, notched 

 or unequally bifid ; the second is 14.-2 inches long, of the form and texture 

 of the other scales, not perforated by any organ, but often at last severed 

 in two halves. 



Flower ani Fruit. — A few observations must suffice here. I will only 

 mention that the prolonged and thickened commissure of the anthers 

 forms a hook, which in the bud is curved over the torus, that of the inner 

 filaments much more than that of the outer ones. The pollen grains are 

 smooth and globular, 0.04 lines in diameter. I find the number of carpels, 

 and consequently of nuts, on the torus between 12 and 31, arranged in 

 two or in three circles: 9-15 in the outer, 3-U in the second, and 1-5 m 

 the third circle, when present. The carpels, in the smallest flower-buds 

 examined, were indicated bv cellular protuberances on the receptaculum 

 in the sime plane as the smaller cellular masses destined for anthers, of 

 0.05 line diameter; the torus, growing up. gradually encloses them, 

 leaving only the stigma free. The knob of the carpel is always directed 

 towards the periphery of the torus, and the micropyle of the anatropous 

 ovule towards the centre; the channel of the perforated stigma leads into 

 the cavity of the carpel near the short funiculus, away from the micro- 



