66 Brady^ on the Seed of Dictyoloma Peruviana. 
render the rest of my paper more intelligible^ I may be 
allowed to advert to it in a few words. 
When mature, it is a roundish or kidney-shaped seed, about 
a quarter of an inch in diameter, thickest at the centre, and 
gradually thinner towards the outer edge, which we find ex- 
panded into a thin, membranous wing (PL VII, fig. 5). 
Careful examination shows that the cells on the outer layer 
of the testa, which appear on the body of the seed in the 
form of irregular projections, are, towards the circumference, 
excessively developed, especially in length, and it is in this 
way that the expansion alluded to is formed. The side walls 
of these elongated cells become much thickened in the 
process of growth, thus afibrding to the wing the necessary 
strength and firmness, whilst the front and back walls retain 
their original transparency, being marked only by a very 
delicate subspiral deposit. A glance at the accompanying 
sketch (fig. 6) will supply any deficiencies of this verbal 
description. 
This introduction will, I trust, render intelligible the more 
complicated structure which is observable in Dictyoloma 
Peruviana. A general idea of this beautiful seed may be 
gathered from fig. 1. Endlicher's description of it, which 
is very defective and partially incorrect, runs thus : — Semina 
late reniformia, compressa, dorso in alas duas parallelas 
radiatim reticulatas, fibra marginali conneooas expansa^ sinu 
ventrali umbilicata.'^ As we may infer from the above, 
it is broad, kidney-shaped, and flattened. Besides possessing 
a wing formed in a similar manner to that of Eccremocarpus, 
by the expansion of the testa round the edge, there are 
several succesively smaller, lateral wings in the same plane, 
the margins of which form a series of concentric rings over 
either surface of the seed. These smaller wings lie close to 
the surface, and appear almost like a continuous coat of 
connected cells ; indeed, those nearest the centre seem to be 
more or less connected through their entire length to the 
seed itself, the outer extremities only being raised above 
the general surface, thus keeping up the appearance of con- 
centric rings above alluded to. The alse, as they approach 
the circumference, become successively larger, and to a 
greater extent free. The sectional sketch, fig. 2, represents, 
as nearly as I can make out from the small materials at my 
command, the arrangement of the wings. 
But perhaps the structure of the alse themselves is the 
most remarkable feature in the case. Each wing appears to 
consist of a series of radiating fibres connected at their outer 
margin, the spaces between them being left quite open. 
