AFFINITIES OF BALANOPHORE^. 25 



amongst Cornece, Loranthacece, and several other Orders in ^liich the ovule is reduced to 

 a nucleus. The homogeneous emhryo is (as indicated by Brown and GrifTith) a form of 

 that organ which, if taken alone, appears to he of little value in a systematic point of 

 view ; for it occurs in various genera belonging to natural families A^'hich have, tj-picaUy, 

 highly developed embryos ; and this argimient is fui'ther weakened by the fact of Cyno- 

 morium, Surcophyte 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, BalanophorecB may in one sense be considered a strictly limited one, not 

 passing dli-ectly into any other, except perhaps thi'ough Gunnera into Haloragece ; 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 relationsliip with other Orders, and regarding it per se, it is mot 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, Balanophorece may in some respects be considered to hold a very high 

 one. Thus : — 



1. The monoecious and generally dioecious flowers show that either a whole plant, or a 

 considerable 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 simplicity which assumes the leaves composing the floral whorls to 

 be developed free from one another. 



5. The cohesion of the anthers and fUaments in most of the species is a fiirther instance 

 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 poUen-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 aU theoretical inquiries which are not based upon fixed prin- 

 ciples, so in this as to the comparative rank of Balanophorece, 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 theu- 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 



