AFFINITIES OF BALANOPHOREÆ. 25 
amongst Corneæ, Loranthaceæ, and several other Orders in which the ovule is reduced to 
a nucleus. The homogeneous embryo is (as indicated by Brown and Griffith) a form of 
that organ which, if taken alone, appears to be of little value in a systematic point of 
view; for it occurs in various genera belonging to natural families which have, typically, 
highly developed embryos; and this argument is further weakened by the fact of Cyno- 
morium, Sarcophyte and Mystropetalon having very obvious embryos immersed in 
| albumen. $ 
To parasitism, as a character of systematic value, I need scarcely allude; its invalidity 
being universally conceded. 
As an Order, Balanophoreæ may in one sense be considered a strictly limited one, not 
passing directly into any other, except perhaps through Gunnera into Halorageæ; and 
forming a sufficiently natural assemblage of species, though, owing to causes I have 
repeatedly dwelt upon, not easy of exact definition. Putting aside any consideration of 
. its relationship with other Orders, and regarding it per se, it is not easy to say whether 
it should abstractedly be considered as ranking high, or the contrary. Assuming that 
the conventional definition of perfection in use amongst zoologists is applicable to the 
vegetable kingdom, and which argues that a high degree of specification of organs and 
morphological differentiation of them for the performance of the highest functions, indi- 
cates a high rank, Balanophoreæ may in some respects be considered to hold a very bigh 
one. Thus:— : 
1. The moncecious and generally dicecious flowers show that either a whole plant, or a 
eonsiderable portion of it, is specialized for each sex. 
2. The great difference between the perianths of the sexes indicates a very high degree 
- of morphological differentiation for each special function or sex. 
3. The deviation of the parts composing the perianth of all the species from the com- 
mon leaf-type indicates great differentiation. 
4. The cohesion of the parts of the perianth in the male flower is a further deviation 
from that theoretical simplieity which assumes the leaves composing the floral whorls to 
be developed free from one another. 
5. The cohesion of the anthers and filaments in most of the species is a further —Z 
of specialization of the same nature. 
6. The adhesion of the perianth of the female flower to the ovary shows its special 
adaptation as a protecting organ to be carried to the highest degree. 
7. If it is safe to assume that either of the two perfectly equal and similar styles of the - 
group Distyli is capable of conveying pollen-tubes to the solitary ovule, we have here 
a very remarkable case of specialization; for these two styles undoubtedly belonged 
originally to as many ovaries, though finally specialized for the use of one only. 
As however is the case in all theoretical inquiries which are not based upon fixed prin- 
ciples, so in this as to the comparative rank of Balanophoree, there is much to be said on 
both sides. The reduced axis, the imperfect vascular system, the absence of leaves in many 
of the species, and their reduction to scales without stomata in the remainder, together 
with the invariable absence of a corolla, and of integuments to the ovule, are all evidences 
of a very low development. Whatever difference of opinion there may be as to the posi- 
VOL. XXII, E 
