496 Transactions. — Miscellaneous. 



perate climate in the antarctic regions, this mode of distribution may have 

 sufficed to introduce some species into New Zealand, but it appears some- 

 what improbable that it still continues to any considerable extent. A cor- 

 rect knowledge of the oceanic currents which impinge on our coasts, will 

 alone enable us to form an estimate of this means of plant immigration, and 

 this information I do not possess. 



Having considered very briefly these modes of plant dispersal, and 

 noticed the geographical distribution and relationships of those genera 

 which have been affected chiefly by their modifications of form, I would 

 take a brief glance at the endemic forms which occur so abundantly in our 

 islands. As these have probably all originated in or near the localities 

 where they now exist, they can only aid us in the solution of the present 

 question by their affinities. Many of these affinities are very difficult to 

 establish, but in the majority of cases where the relationship of our endemic 

 species to the flora of other countries is evident, it is found that Australian 

 forms greatly predominate. Long isolation, together with complete change 

 in their environment, has probably served to modify many of the immi- 

 grants, so that their affinities have become obscured, and this has acted in 

 many cases so effectually as to mask them altogether. Usually variation 

 first appears in the habit of the plant, and we see .this in the form of the 

 foHage, etc., of Ranunculus lyallii, our coriaceous Veronicas, Olearias, 

 Ligusticums, etc. The same change is seen in recently-introduced plants, 

 as in the common watercress (Nasturtium officinale), which in New Zealand 

 rivers shows a tendency to assume a very different habit from its European 

 parent. Protection against some forms of insect enemies, probably Orthop- 

 terous, appears also to have played an effectual part in modifying the 

 epidermal structures of many of our species, and may partly account for 

 the prevalence of coriaceous-leaved and woolly plants, among the alpine 

 species in particular. But we have little data here to go upon ; and before 

 passing on to the last part of this address I will just point out a few pecu- 

 liarities of structure in our plants, which are of interest and full of sugges- 

 tiveness. 



One of these is the scarcity of spiny or prickly plants. As the func- 

 tion of spines and prickles is probably that of defence against mammalian 

 enemies, we can readily understand the paucity of such contrivances in our 

 plants. Even the apparent exceptions go to prove the rulean nearly every 

 case. Where such defensive modifications do occur, we notice that the 

 plants are usually to be found outside of New Zealand, and are most prob- 

 ably of foreign origin, their weapons of defence having been developed in 

 countries where they were of service, and the New Zealand immigrants not 

 having had sufficient time to lose them. Thus Discaria toumatou has its 



