394 
AMERICAN JOURNAL OF BOTANY 
[Vol. 8 
a consistency in abortion, the posterior carpel being the sterile carpel in the 
hermaphroditic flower and the more greatly reduced carpel in the staminate 
flower; and the lateral strands of the pistillate flower (figs. 9-12, 0^ and 0^), 
regarded as dorsal strands of abortive carpels, are suppressed in the abortive 
pistil of the staminate flower. 
MORACEAE 
In brief, the plants of this family are woody with small flowers usually 
in dense clusters, unisexual; the perianth 5- to 4-parted, stamens equal in 
number with, and opposite to, the parts of the perianth; ovary one-celled 
with single pendulous ovule, styles 2 or i. The ovule is "basal" (i, 9) 
in a few species. 
Mortis alba L. presents in the pedicel of the pistillate flower a stele of 
four traces (PI. XIX, figs. 2, 3). From these four traces pass off in a 
decussate manner the posterior and anterior traces, followed closely by the 
lateral (fig. 4, p, p^). These traces supply the four perianth parts, and in 
each part the bundle separates into three strands (figs. 4, 5, p, p^). The 
floral axis above the point of departure of the perianth traces continues as 
four strands, posterior, anetrior, and two lateral. The anterior and pos- 
terior strands are the dorsal bundles of the two carpels (PL XIX, figs. 4-9, 
I, and pass on into the styles. The two lateral strands, as in Ulmus, 
approach each other as they ascend, unite, and pass upward into the ovule 
(PI. XIX, figs. I, 4-7, 0). In Mortis alba these two strands to the ovule do 
not receive any evident vascular supply from the anterior carpellary strand 
as figured by Welsford and Benson (22) for M. nigra. 
The pedicel of the staminate flower (PI. XIX, fig. 10) shows many 
strands in the stele which organize into four strands in the base of the flower. 
From these, four traces pass off decussately and each soon separates into 
strands to the perianth parts and to the stamens. The dorsal carpellary 
supplies persist in the abortive pistil of the staminate flower (PL XIX, 
fig. 10, I, ii). 
An interesting difference in the vascular supply to the perianth parts of 
the pistillate and staminate flow^ers is that there are three traces to each 
part in the former and only one in the latter. In the pistillate flower, the 
perianth persists in the fruit as a fleshy organ and calls for a vigorous 
vascular supply. The staminate flower functions to the time of pollen 
production and then falls. As a result, the vascular supply to its perianth 
has degenerated to a single weak strand in each lobe. This is an illustration 
of what happens frequently in members of the Urticales. The organ de- 
generates to the extent that the apparent demand for it decreases. 
Madura pomifera (Raf.) Schneider has its pistillate inflorescence in a 
dense, succulent head, the individual flowers being sessile. A transverse 
section of the inflorescence axis below the bases of the flowers shows the 
many pedicellar steles surrounded by a continuous, extremely delicate, 
