G. M. Thomson. — On the Origin of the New Zealand Flora. 493 



ing to a specially South American order, is similarly characterized, but 

 its occurrence here has no special significance, as Australia possesses an 

 endemic species as well as New Zealand. The genera Epilohium and Par- 

 sonsia both have tufts of hair on their seeds to aid in their dispersal ; the 

 former is a very wide-spread genus in all temperate regions, and some of its 

 species are common to both hemispheres ; while the latter is an Asiatic and 

 Australian genus. The only other contrivances which aid in the wind- 

 dispersal of our New Zealand plants are wings on the fruits or seeds. These 

 occur, but feebly developed, on the nuts of Fagus, and on the seeds of 

 Knightia, Dammara, and Libocedrus. The first of these occurs in both the 

 north and south temperate regions ; but our and the Australian species are 

 all probably of antarctic origin. The second genus has one New Caledonian 

 representative, and the third is Australian, Malaysian, and Polynesian in 

 its distribution, while Libocedrus is found only in New Zealand and South 

 America. 



While special adaptations for wind-distribution are apparently few in 

 New Zealand plants (if we except the Compositse), there are no doubt many 

 seeds which are readily blown about by reason of their small size and light- 

 ness. I have no data to guide me here, but will instance the order 

 Orchideffi, all the species of which have minute, light seeds, and all the 

 genera of which are either Australian or from further north, or have an 

 Australian facies. 



(2.) The second mode of dispersal mentioned is by means of birds, and 

 this is accomplished in three ways— "either by swallowing fruits and reje'ct- 

 ing the seeds in a state fit for germination, or by the seeds becoming 

 attached to the plumage of ground-nesting birds, or to the feet of aquatic 

 birds embedded in small quantities of mud or earth." With regard to the 

 first of these modes, it is probable that the bright colours of most succulent 

 fruits serve to render them conspicuous and attractive to birds, which are 

 thus led to swallow them. But most seeds, enclosed in fleshy pulp, are 

 furnished with a hard shell or test, and most fruit-eating birds have a very 

 soft gizzard, incapable of grinding-up the food which they eat, and so it 

 happens that these birds become the unconscious means of distributing 

 plants producing such succulent fruits. I find that altogether some 59 

 genera of plants in New Zealand produce succulent fruits, mostly dru- 

 paceous, that is, having the inner layer of the pericarp hard or stony, so 

 as to protect the seeds. And of these no less than 41 genera are common 

 to these islands and Australia or the tropics of the Old World. Only 

 18 of these genera occur also in America, and their range is either very 

 wide, as in the case of Myrtus, Eugenia, Solanum, Cassytha, and Astelia, 

 or they are of antarctic distribution, and have in most cases invaded 



