G. M. Thomson.^ — On the Fertilization of FLoivering Plants. 265 



capsules and seeds. From the great variety of intermediate forms which 

 occur so commonly, I am inclined to think that hybridization goes on fi-eely 

 among the various so-called species. 



Nat. Ord. Fiooide^. 



The flowers of Mesembryanthemum australe are stated to be unisexual, in 

 which case they are probably entomophilous. All the specimens I have 

 examined have been hermaphrodite however, and apparently self-fertilized. 

 The flowers are very conspicuous, but destitute of scent or honey. 



Tetragonia expansa has comparatively inconspicuous and solitary flowers, 

 which are always hermaphrodite. It is probable, therefore, that they are 

 self-fertile, but they are also rendered attractive to insects by the thin layer 

 of honey they contain, while cross-fertilization must often be insured by the 

 fact of their being slightly proterogynous. The stigma is always expanded 

 some time before the anthers dehisce. 



Nat. Ord. Umbellifee^. 



This large order, which is nearly always represented in other parts by 

 hermaxDhrodite flowers, has unisexual forms in three of its New Zealand 

 genera. 



In the genera Hydrocotyle, Pozoa, and Crantzia, the flowers are very 

 small and inconspicuous, and the plants themselves are small and low- 

 growing. Oreomyrrhis has also small flowers, though more conspicuously 

 placed, while the same remark applies to the smaller forms of Ligusticum. 

 Daucus brachiatus has minute red flowers, which are somewhat conspicuous 

 when abimdantly produced. I am not aware whether the flowers of these 

 different plants are visited by insects or not. 



Apiuin, like the foregoing, has hermaphrodite flowers, which are con- 

 spicuous in A. australe, but much reduced in A. filiforme. The former 

 secrete honey and are slightly fragrant. I have not noticed either pecu- 

 liarity in the flowers of the latter. 



Aciphylla squarrosa and A. colemoi have dioecious flowers, the male being 

 furnished with an imperfect pistil. They produce abundance of honey, are 

 very fragrant, and are produced in such mass (forming elongated panicles 

 two to four feet long) as to be extremely conspicuous objects. They are 

 entomophilous, and are frequently seen to be covered with various species of 

 Coleoptera and Diptera. Professor Hutton informs me that Lyijerobius 

 huttoni and Piophlceus inniis, two large weevils, are only found on plants of 

 this genus, and that Cyttalia griseiptila is much more abundant on them than 

 anywhere else. He is of opinion, however, that Lyperohius huttoni lives on 

 the juices of the leaves. 



The larger species of Lif/wsiicww which I have examined — namely, L. inter- 

 medium and L. lyalli, are also usually dioecious. The flowers are sweet- 



34 



