STRUCTURE. 89 



to terminate in the axile process. From the bundles of the outer ring 

 branches are given off to the petals and stamens on the one side and to 

 the walls and partitions of the ovary and ultimately to the ovules on the 

 other. Finally, a bundle extends into each carpellary style. In Syn- 

 carpiae the bundles of the inner ring, like those of the outer, are irregularly 

 placed with regard to the carpels, and they seem to unite among them- 

 selves by oblique branches ; but in Apocarpiae there are one or two 

 bundles in the inner edge of each carpel, and these are separated from 

 neighboring ones by the divisions between the carpels. The inner 

 bundles branch copiously into the partitions between the cells of the ovary 

 in order to connect with the ovules. The bundles are so oriented as to 

 bring xylem next to the ovary cells and phloem away from these, that is, 

 normally with regard to the carpel itself. Consequently the bundles of 

 the outer ring have xylem on the axial side, but the inner ring has phloem 

 toward the axis. In the partitions the bundles nearest one cell have their 

 xylem next to that cell ; since those on the other side of the partition are 

 similarly arranged, the two sets have their phloem sides turned toward one 

 another. The central axile bundle of N. odorata has one or two spiral 

 trachese with phloem all round, but especially thick on two opposite sides. 

 Some peculiar vascular bundles occur in the ovary wall. The largest 

 bundles of this type have an outer mass of phloem, then a band of xylem; 

 this is followed by a band of small-celled parenchyma, and this by another 

 xylem band equal to the former. These are comparable with the smaller 

 veins of the leaves where two bundles stand one above the other ; in the 

 ovary the phloem of the upper bundle is suppressed and the intervening 

 parenchyma reduced. 



The fruit of a waterlily is technically a berry. The outer wall of the 

 ovary remains firm, but its inner tissues become soft and mealy, i. e., the 

 cells easily separate from one another. The ovary-cells are filled with a 

 greater or lesser number of hard spheroid or ovoid seeds embedded in 

 mucilage, and each surrounded with an aril. Dehiscence is irregular ; the 

 fruit simply bursts open by the growth of the arils and swelling of the 

 mucilage. In N. flava, however, there is a decided tendency for the car- 

 pels to separate, still containing the seeds. The ripening of the fruit 

 takes place under water, during which time various changes occur in the 

 floral leaves. In Castalia these completely rot away, leaving only small 

 scars. In Lotos about half an inch of the bases of the outer stamens 

 remains attached to the fruit. In N. ainazointm the sepals persist and the 

 other parts of the flower may be only partly decayed. In Brachyceras 



