TERTIARY FLORA. PAL 
Island (virtually part of the continent) a number of fossils of 
Tertiary age were discovered. These included the following New 
Zealand genera: Pukatea (Laurelia), now represented by only one 
Fuegian and one New Zealand species); rewarewa (Knightia), a 
genus of only 3 species (1 New Zealand, 2 New Caledonia), but the 
Antarctic plant is related to the New Zealand species and not to the 
New Caledonian, which belong to a different section of the genus; 
horopito (Drimys), a genus of 12 species—Fuegian, New Zealand 
(83 species), Australian, New Caledonian, and Malayan (New Guinea 
and Borneo, in the mountains); southern-beech (Nothofagus). The 
occurrence of these fossils is a matter which must be carefully con- 
sidered when dealing with the origin of the New Zealand flora. 
Remnants of an ancient Tertiary flora are not wanting in New 
Zealand itself. In Otago and Canterbury, as also in other localities, 
a good many impressions of plants on rock have been collected. 
Some of these were studied and described by Ettingshausen. He 
refers a considerable number to genera of the Northern Hemisphere 
that no one would eyer expect to have been able to reach New 
Zealand in such numbers. Amongst such genera are oaks (Quercus), 
alders (Alnus), elms (Ulmus), and maples (Acer). There were also 
certain of the existing New Zealand genera, and others of a New 
Zealand type. Judging from Ettingshausen’s figures of the fossils, 
it seems clear that there must be great doubt as to the accuracy 
of his identifications. If these genera were present, there must have 
been one universal temperate flora—a happening hardly conceivable 
with the tropical climate as a barrier. This fossil flora is nevertheless 
a fact. It teaches clearly that many genera and species have passed 
away, just as the present species must in the lapse of the long years 
pass away also. It is to be sincerely hoped that some one well versed 
in the flora of New Zealand will thoroughly study these fossils ; no 
purely scientific work is more wanted. 
It has already been explained in Chapter II that many plants 
greatly alter their form according to a change in their environment, 
but such a change of form is usually not permanent. In other cases 
it is abundantly proved that a species may in course of time be so 
completely altered, through some agency not yet known, that a new 
species has arisen. It is from changes of this kind that all the species 
of the earth are supposed to have originated. Such species are said 
to be “‘evolved”’ from other species, and the process is called 
