T. Holm — Mollugo verticillata L. 527 



developed, while only one (L 8 ) is as yet visible of the second 

 pair. It is now interesting to notice that the first two leaves 

 (L 1 ) are of unequal size, the posterior being the larger, thus 

 demonstrating the fact that, in this case, the anisophylly is not 

 produced by any difference in exposure to light ; the little 

 shoot is erect, and the leaves are equally exposed to the effect 

 of the sunlight. Nevertheless, as shown in figure 3, three dis- 

 tinct pairs of leaves develop in this way, with a remarkable 

 tendency to attain a larger size on one side of the shoot than 

 on the other. This plant (fig. 3) is, also, a young seedling 

 with the cotyledons (Cot.) plainly visible, and we notice, 

 furthermore, a very distinct, central internode which bears a 

 few flowers and green leaves. At this stage the hypocotyl (ri.) 

 has become bent down toward the ground by the weight of 

 the leafy rosette ; thus we have before us an indication of the 

 future habit of the plant already illustrated by this veiw young 

 specimen, viz. : a basal rosette of crowded, opposite leaves of 

 unequal size, and a terminal shoot which begins with a stretched, 

 plagiotropic internode terminated by an inflorescence, which is 

 preceded by a few pairs of leaves. There is, thus, an alterna- 

 tion of short and of long internodes, while the foliage shows 

 the same anisophylly throughout, the leaves upon, or nearest, 

 the upper face being distinctly smaller than those of the lower 

 face of the shoot. No stipules are developed, but the leaves, 

 the large as well as the small, bear pluricellular, glandular 

 hairs (fig. 9) at the base, near the margin and along the dorsal 

 face of the midrib. Very minute leaves occur, also, at the 

 base of some of the flower-stalks and represent fore-leaves, as 

 described by Eichler.* The apical portion of a branch from a 

 mature specimen is represented in figure 4. We notice in this 

 branch the long internode J, which bears four pairs of leaves, 

 of which the first pair (L 1 ) contains the smallest and largest of 

 all the leaves developed, the inner pair (L 4 ) show the gradual 

 decrease in size when compared with the outer (L 3 -L 3 ), and 

 one of these is frequently completely suppressed. Further- 

 more is to be noticed that the lateral shoot (S.) is developed 

 from the axil of a large leaf (L 3 ) on the outer face of the 

 mother-shoot. 



The anisophylly illustrated by Mollugo thus shows the much 

 farther development of the leaves of the lower face of the 

 stem, than of those of the upper. Furthermore, the ramification 

 of the stem shows us, that the strongest lateral branches con- 

 stantly develop from the axils of the largest leaves, rendering 

 the complete growth of the plant horizontal, and more or less 

 closely appressed to the ground. As already mentioned, this 



* Bliithendiagramme, vol. ii, Leipzig, 1878, p. 119. 



