Laing. — On the Alga of Neiv Zealand. 311 



subtle inherited tendencies. Such a variety as Hormosira 

 sieberi, some bleached forms of Gystophora, and a certain 

 variety of Jania micrarthrodia, are due to the plants living in 

 pools that can only be reached by the highest spring-tides. 

 Situations and external circumstances likely to modify the 

 normal form of the plant should always be noted in collecting 

 varieties. 



It is rather remarkable that while we have so many endemic 

 species so few of the remainder should be exclusively Austral- 

 asian. We have already seen that about a fourth of these 

 belong to the Fucacece, the remaining three-fourths are Flori- 

 dean. The green seaweeds are apparently too widely dis- 

 tributed to show any distinct kinship between the two 

 districts. Future observers should remember that we may 

 have from time to time adventitious additions to the Austra- 

 lian element in our flora. In these days of copper-painted 

 and copper-sheathed ship-bottoms it is perhaps hardly likely 

 that ordinary traders will bear across the Tasman Sea many 

 living Alga? attached to their sides ; but I have known several 

 instances where hulks have lain long in some Australian port 

 and then been brought across to New Zealand to do service 

 here. Such vessels, if undocked preparatory to the journey, 

 would bring across with them many living specimens of Aus- 

 tralian animal and vegetable life. 



The most interesting element amongst our marine Algse is 

 undoubtedly the antarctic, which may be again subdivided as 

 follows : — 



New Zealand antarctic, Tasmania (sometimes Australia) . . 12 



New Zealand, South America, and antarctic islands . . 8 



New Zealand and antarctic South America . . . . 6 



New Zealand and antarctic islands . . . . . . 5 



31 



As these results are of some importance I attach a complete 

 list of these species, giving details of the external distribution. 

 Now, it is to be noted that no less than 10 per cent, of our 

 species are antarctic in distribution ; of these, a half, or 50 per 

 cent., are found in Kerguelen, and about the same percentage 

 (twenty species) of South African Algas are also found there ; 

 and this notwithstanding that South Africa is separated from 

 Kerguelen by only 50 degrees of longitude, and New Zealand 

 is separated from it by about 150 degrees. Moreover, it will 

 be seen from the detailed list that no plant is common to the 

 three regions. 



Again, seven plants occur in New Zealand, the antarctic, 

 and Tasmania, but not on the mainland of Australia. One or 

 two of them, of course, may yet be found in Victoria ; but 

 several of them are so conspicuous that they could not be 



