STUDIES IN ARACEAE 
JAMES EtLttis Gow 
(WITH PLATES IV-VI) 
I. NEPHTHYTIS GR THII 
In the fall of 1906 the writer enjoyed the privilege of examining 
the extensive collection of tropical aroids in the greenhouses of the 
New York Botanical Gardens, and of collecting material for an 
investigation of the embryo sac and embryo. Among other species, 
Nephthytis Gravenreuthii was selected for this purpose. A con- 
siderable amount of material was obtained, illustrating stages from 
the archesporium to the mature embryo. 
Ovary.—The genus is characterized by a single simple carpel 
which shows a tendency toward a slightly unsymmetrical develop- 
ment, the stylar canal never being in the axis of the carpel (jig. 2). 
The carpel is short and thick, the stylar canal very short, funnel- 
shaped, and lined with viscid conducting cells. On the interior of 
the carpel the conducting cells reach a considerable length and come 
in contact with the ovule on all sides, sometimes reaching quite to 
the micropyle. 
OvuLE.—The ovary contains a single, basal, anatropous, cauline 
ovule. Probably the single,! basal, orthotropous ovule is the most 
primitive kind, and in Arisaema we find an orthotropous ovule, but 
there are typically four ovules; and while they are cauline in origin 
they occur as lateral outgrowths of a suppressed placenta, the ill- 
defined point of the placenta representing the axis of the flower. The 
Single axial ovule, even though it be anatropous, is no doubt a sim- 
pler type than this ; and when we compare it with such a form as 
Dieffenbachia, in which each ovule, arising from the partially sup- 
Pressed placenta, is surrounded by a separate carpel, its primitive 
character becomes yet more apparent. 
In general, the ovule of the species now under discussion is peculiar 
for its Massive integuments and for the poor development of the 
nucellus. The latter consists at first of a single row of cells sur- 
35] [Botanical Gazette, vol. 46 
