OF SANTALUM ALBUM. 75 
vertical position (fig. 33), or with the cotyledons curved a little towards the lateral 
basilar scar just mentioned (fig. 35). The radicle is at the upper end of the seed and 
terminates in an acute apiculus (Tab. XVIII. figs. 34 & 36). 
In the mature fruit the mesocarp forms a hard shell, outside which the epicarp forms a 
thin layer of pulpy substance (Tab. XVIII. fig. 22). The woody shell is slightly pointed 
and trigonal above, presenting three converging ridges (Tab. XVIII. fig. 81) when the 
epicarp is removed. Within the woody mesocarp the albumen or endosperm of the 
seed lies free; the coat formed by the embryo-sac is no longer distinguishable, but the 
endosperm is covered with brownish membranous scales (Tab. XVIII. fig. 82), composed 
of compressed withered fragments of the lax cellular tissue of the obliterated parenchy- 
matous endocarp. 
The above observations confirm in almost every respect those published by Griffith in the 
Transactions of the Linnean Society, the main point of difference lying in the statements 
made with respect to the phenomena presented at the summit of the embryo-sac at the 
time of fertilization; in which my account is strongly opposed to those given by that 
author, not only in Santalum, but in Osyris and the Loranthacee. Notwithstanding 
the high value I attribute to Griffith’s labours, increased and confirmed by the researches 
now brought forward, I feel very confident of the correctness of the account I have given 
of the origin of the embryo from a pre-existing germ, and I have little doubt that the 
process of fecundation is such as I have described in Osyris, and the other cases. The 
importance attaching to the truth of the view I have propounded will be farther illustrated 
below. 
Every one who has studied the development of the ovules of Santalum, and the allied 
genera, has been struck by the remarkable anomalies which present themselves, The 
entire protrusion of all the (apparently) essential part of the embryo-sac from the apex 
of the nucleus, the development of the endosperm in the external compartment of the 
sac, altogether independently of the nucleus, are very remarkable; while the posterior 
development of the embryo-sac is no less singular. The idea has been suggested that the 
entire central body here described as a free placenta with the ovules reduced to nuclei, 
might be one ovule with three embryo-sacs; and also that the central body is all placenta, 
the nuclei being merely the funiculi of ovules reduced to embryo-sacs. There does not 
seem to be sufficient ground for either of these assumptions, although the former is in 
some respects plausible. : : 
The i reason which could be advanced in favour of the second idea, is the nn 
rently abnormal position of the embryo, the coty. ledonary extremity of nee "rs m 
apex of the nucleus, and the radicle end pointing in the direction caeli a n 
nucleus. But this is rather an apparent than a real irregularity. It wo - a senum 
insistence upon terms to call that end of the embryo-sac engaged "M e ede ifr. 
nucleus, the micropyle-end; it is really the middle, and the erhbryo-sie is in ampy 
: : ine in the interior of the nucleus, while the 
lotropous, its organic base or chalazal end being m ed up so as to lie (out- 
micropyle-end is prolonged out beyond the micropyle, and turned up 
side) against the chalazal end. e i 
In regard to the first of the two views above referred to, the only | which 
