Campbell.—Studies on the Araceae. 5 
a little before the other, but this point was not certainly 
determined. 
As the flower grows, the central portion projects strongly, 
and may be called the placenta, as the ovules arise from it as 
lateral outgrowths in the axils of the two carpellary leaves 
(Fig. 3). The ovules must be regarded as axial structures 
in Diejfenbachia , which thus agrees with most other low 
Monocotyledons which have been investigated. Indeed, there 
is constantly increasing evidence to show that the single axial 
ovule is the primitive form. 
The carpels grow up rapidly about the ovule, and arch over 
toward the placenta (Fig. 3). They become very thick, so 
that the ovarian cavity is small, and a narrow canal is left 
between the thick margin of the carpel and the central 
columnar placenta. Later, the upper surface of each carpel 
develops a large button-shaped stigma. The carpels are 
coherent at their lateral edges, but there is a deep suture, and 
the two stigmas are quite separate. 
The young ovule projects obliquely from the base of the 
placenta, and very early a vascular bundle becomes evident, 
traversing the short thick funiculus, and joining a bundle in 
the placenta. The ovule at this time is nearly straight. The 
two integuments are indicated and the archesporial cell can 
be distinguished. Very soon the growth of the upper side is 
accelerated, and the ovule assumes the anatropous condition 
found in the later stages. 
The Male Flowers. 
The male flowers in Dieffenbachia completely cover the 
upper part of the spadix. Each consists of a synandrium 
made up of a varying number, usually four or five, of 
coherent stamens borne upon a peltate receptacle. In cross- 
sections of the young spadix, the young synandrium appears 
as a mushroom-shaped elevation (Fig. 16) strikingly resem¬ 
bling a corresponding stage in the development of the sporo- 
phyll in Equisetum. About the margin and projecting 
