MR. J. MIERS ON THE FAMILY OF TRIURIACER. 51 
rescence, unisexual flowers, simple perianthium, similar in both sexes, nearly cleft to its 
base into regular segments, with a valvate sestivation and a cellular epidermis ; the male 
flowers furnished with few stamens, which are seated opposite the segments upon a fleshy 
disc, or more or less prominent androphorum ; very numerous distinct carpels in the female 
flowers, having a more or less lateral style, and a single erect ovule, and offering a seed of 
most peculiar structure. These characters do not conform with any other natural family ; 
for which reason, when Triuris only was known, I suggested it should form the type of a 
new order. In regard to the affinities of this group of plants, it is manifest that they 
bear:no analogy with Menispermee or Smilacee, as Mr. Gardner at first inferred; nor can 
they be held related to Artocarpee, where that zealous botanist, following the example 
of Endlicher, referred Sciaphila and Hyalisma. Their structure, totally different habit, 
simple style, erect ovule, arilliform envelope, and acotyledonous seed, distinguish them in 
the most decided manner both from Artocarpee and Urticeæ. In order to arrive at their 
real position in the natural system, we must first determine in what class to seek their 
" nearest alliance. 
The facts before shown lead to the inference, that the seed of the Z'riuriacec is not only 
acotyledonous, but inembryonal, a fact not singular in the history of Phænogamous plants. 
But does the absence of the usual elements constituting an embryo, viz. cotyledon, radicle, 
and plumula, imply the want of the ordinary function of the reproductive power of the 
plant from its seed so constituted ? It appears that the presence of such elementary parts 
is not always a necessary condition to the capacity of vegetable reproduction. According 
to the views of modern physiologists, the embryo is but a normal condition of a leaf-bud 
and stem, whose gradual increment is due to certain secretory deposits, regulated by fixed 
laws of cellular expansion, thus producing a highly complicated or low degree of vascular 
development in every phænogamous plant, from the smallest herb to the most gigantic 
tree of the forest. But in those plants destitute of real leaves, and composed of little more 
than simple cellular tissue, void of green colour, and of the fibres and ducts that enter into 
the structure of most other vegetable substances, we can hardly expect to meet with a 
reproductive embryo organized in the form of such a normal bud; and it is only consist- 
ent with so simple a structure, to expect a nucleus equally simple in its nature, formed 
merely of an aggregation of eytoblasts, which, under favourably-exeiting influences, are 
endowed with the faculty of self-development. Indeed, we have no satisfactory evidence 
of the existence of an embryo, in the ordinary sense of this term, in the seeds of Burman- 
niacee, &c., notwithstanding that we know they must be constantly reproduced from their 
seeds. 
Mr. Robert Brown, in his learned memoir upon Rafflesia, in the nineteenth volume of 
the Society's Transactions, has shown that the seeds of that genus, although albuminous, 
possess an embryo of the most simple and reduced form ; but the Balanophoree, which 
that most distinguished botanist holds to be quite a distinct and even distant family from 
the Rafflesiacee, have been shown by Mr. Griffith to be truly inembryonal; and in his 
paper on Balanophora * he describes the structure of its nucleus, and the contents of its 
cells, as being precisely similar, even in words that answer ın every respect for all that is 
* Trans. Linn. Soc. vol. xx. pp. 98, 101 and 102. 
H 2 
