the same time. The immigrants on arrival are certainly in an exhausted state and physically incapable of defending themselves from the assaults of enemies. The shores of the new land are patrolled by great numbers of gulls and similar predaceous birds, which would make short work of any travel-worn immigrants that landed and did not immediately find cover. The chances of getting food are also problematical. But even assuming that the individuals survived and throve, the chances of their finding mates are very remote; so that altogether the probabilities are against the establishment of the species. As a matter of fact they do not succeed. The only bird which appears to have come into New Zealand since the days of European settlement and to have established itself, is the Wax-eye or Blight-bird (Zosterops cœrulescens).

In taking a survey of the existing Flora of New Zealand in connection with its relationship to other plant-associations, and taking Cheeseman's Manual as my authority for the following figures, I desire to state at the outset that I do not attach too much importance to numerical comparisons, because I realise the enormously different values attached by systematists to different species. These values depend largely upon the personal equation, and further on the amount of detailed study given to any specified groups of organisms. There are certain genera of New Zealand plants which are apparently in a state of flux even at the present time. These have been submitted to close examination, a vast amount of material has been gone through, and in consequence innumerable differences have been recognised, and a large number of species defined. Such, for example, are Ranunculus with 37 New Zealand species, Epilobium 28, Coprosma 39, Olearia 35, Celmisia 43, Senecio 30, Veronica 84, and Carex 53. Many of these are sharply defined, easily recognised species, but for others the specific diagnosis is only the central rallying point for a large group of individuals showing considerable divergencies in many directions. I am safe in asserting that if similar detail were gone into with all the plants grouped under such common names as, for example, Acana microphylla, Gaultheria antipoda, or Pimelea lævigata, and many others which might be named, it would be found that each deserves to be separated into a group of distinct species. Keeping this reservation in mind, we can still form an approximate estimate of the relationships shown by any given aggregation of species. Thus of the total number of 1396 species of New Zealand flowering plants recorded by Cheeseman, no fewer than 263 (or almost 19 per cent.) are also found to occur in Australia. Of these 134 occur both in Australia and Tasmania (eight in Tasmania alone), while the remaining 129 have a wider range, some being common tropical or sub-tropical

weeds, while others are found throughout the temperate zone in both hemispheres. The endemic species, which do not range outside of New Zealand, number no less than 1069, or 76.6 per cent. of the whole (viz. 860 dicotyledons and 209 monocotyledons). This brings out the affinities of the remaining elements more strongly than ever, for it shows that of 327 species which are common to New Zealand and other countries, no less than 80 per cent. are also found in Australia, The remaining elements-Antarctic and Polynesian-are few as compared with the Australian.

It would appear from the above analysis that immigration of flowering plants from Australia into New Zealand has been going on steadily, and an examination of many of the individual species leads to the conclusion that much of it is quite recent. Thus of pappus-bearing composites, ten species are confined to New Zealand and Australia1; six more are found in New Zealand and Australia, but have a wider range outside2.

No plant of South American, Polynesian or Antarctic affinity is furnished with a pappus. The list of Australian plants includes four species of Epilobium, furnished with pappus-like hairs on the seed; and 14 species of Orchids (out of a total of 53 species, the remainder being endemic) furnished with very minute light seeds which are easily carried by wind. These facts tend to show that species whose seeds can be distributed by wind are fairly abundant among those plants which are common to New Zealand and Australia, and the probability is that many were thus introduced into these islands3.

I regret that I cannot give the date for the following interesting occurrence (I think it was about 1877), but it was so striking a phenomenon that it fixed itself in my memory at the time. It occurred in Dunedin in the autumn (February or March). One bright forenoon the sky became strangely overcast from the west, and the sun at midday assumed a coppery appearance. Some persons attributed the phenomenon to bush fires in the western districts, but no such fires were recorded anywhere in New Zealand. Others more accurately thought it was due to a smoke-cloud from Australia. This proved to be the case. Vessels voyaging between

1 Celmisia longifolia, Vittadinia australis, Gnaphalium traversii, G. collinum, Craspedia uniflora, Erechtites prenanthoides, E. arguta, E. quadridentata, Senecio lautus and Microseris forsteri.

2 Gnaphalium japonicum, G. luteo-album, Picris hieracioides, Taraxacum officinale, Sonchus asper and S. oleraceus.

3 Linnean Soc. 30th Nov. 1916 (London). Using a wind-dispersal apparatus Mr Jas. Small, M.Sc., found that in a light air the fruit of Senecio vulgaris travelled at the rate of 1.6 miles per hour through the air, and of Taraxacum officinale 1.5 miles per hour.

Australia and New Zealand, and others passing up the east coast of Australia at the time, reported dense smoke-clouds from Gippsland and North-west Victoria, and also the falling of considerable quantities of ash and charred vegetable matter. The westerly winds drove the smoke right across the Tasman Sea, and at a distance of about 1200 miles it still exerted such an influence on the upper atmosphere as to make the whole sky lurid for a period of three or four hours. A wind which could carry such a body of smoke such a distance could probably easily transport seeds and spores, and though the usual course of the wind-currents is not so directly from west to east, yet such high winds apparently do occur, and that not unfrequently.

Another agency by which seeds are carried to oceanic islands is by means of birds, which bear them attached to their feet or plumage, and in some cases carry them in their crops. Darwin, Wallace and others have given numerous instances of this fact in plant distribution1. Apart from regular migrants which come to New Zealand every year from Australia, Polynesia and the Northern Hemisphere, a considerable number of stragglers are blown or stray over from Australia each year. The wonder, therefore, is not that Australian species of plants are met with in considerable numbers in New Zealand, but rather that they are not more common than is found to be the case.

As far as all truly indigenous species of animals and plants are concerned it is quite impossible to give dates for any which may have been introduced in long past ages, as for example those which are common, say, to New Zealand and Australia. But when we come down to recent times and reach the period of human immigration, it becomes possible to give some approximation to definite dates.

According to Maori tradition, New Zealand was discovered by two Polynesian voyagers named Kupe and Ngahue, but authorities are not yet agreed as to the period of this discovery.

The first Polynesian settlement in the time of Toi took place 30 to 32 generations, that is approximately 800 years, ago. On the arrival of these immigrants, they found the east coast, north and Taranaki districts occupied by the Mouriuri, Moriori or Maruiwi folk in considerable numbers, descendants of crews of three drift canoes, which had apparently come from the north-west. Whether these people had brought any animals or plants with them it is now impossible to say. According to east coast traditions, the Toi tribes had the Hue Gourd (Lagenaria vulgaris) in cultivation at an early

1 Darwin in a letter to Dr J. D. Hooker in January, 1860, says: "Birds do not migrate from Australia to New Zealand," a curious error for such a good observer to make, and showing the danger of generalising from imperfect data. Many species regularly cross, notably the Shining Cuckoo and the Dotterel.

period, so that this plant was probably introduced from 24 to 30 generations ago, that is between 1150 and 1300 A.D. Communication was kept up with Polynesia for about 200 years more, new settlers coming over from time to time. The last batch of vessels, including the Arawa, Tainui and other canoes, arrived about 20 generations or 500 years ago, say about 1400 A.D. Reference has already been made to the introduction by some of these early voyagers, of the dog, the native rat, one or more species of flea, and two species of lice.

The Kumara (Ipomea batatas) appears to have been introduced first about 1300 A.D., tradition saying that certain voyagers left Whakatane for Polynesia about that time, for the express purpose of bringing over that plant. Subsequent immigrants by the Aotea, Arawa, Tainui, and other canoes, also brought the plant. Indeed it is probable that it was continuously introduced by many of the new arrivals.

Mr Cheeseman in the Manual (p. 100) states in regard to Pomaderris apetala: "The Maoris assert that it sprang from the rollers or skids that were brought in the canoe 'Tainui' when they first colonised New Zealand." Mr Elsdon Best, to whom I referred this point, tells me that about 1879 he saw a grove of these trees

on a terrace near the mouth of the Mohakatina river. Local natives told him that the tree was called Te Neke o Tainui (the skid of Tainui), and that the grove had originated from the skids of the canoe Tainui, used in hauling the vessel ashore on her arrival here twenty generations ago, the skids having been brought from oversea. On my return to New Plymouth I met Mr Wilson Hursthouse, who, I found, was acquainted with the Maori name of the tree and the myth connected with it.

Pomaderris apetala is an Australian as well as a New Zealand species, but is not found in any part of Polynesia. It is difficult to conjecture, therefore, how such a myth could have arisen.

Perhaps about the same time, that is about 1400 A.D., the introduction of the Taro (Calocasia antiquorum) and the Ti (Cordyline terminalis) took place. One tradition says that they arrived in the Nukutere canoe, brought by one Roua, that is about 500 years ago. The same tradition narrates that the Karaka (Corynocarpus lævigata) was introduced at the same time, by the same individual. If so, it may have been brought from Western Polynesia by way of the Kermadecs, where it is a common tree. At the same time the genus is quite peculiar, and is endemic to New Zealand. If it did not originate in this country, then the home whence it came has lost it, for its botanical position and relationships are by no means clear.

After the arrival of the main migrations about 20 generations ago, there are no definite traditions of further Polynesian immigration,

but voyagers left the shores of New Zealand for Polynesia as late as ten generations or 250 years ago, and presumably others arrived from time to time.

With the arrival of Captain James Cook in New Zealand we can begin to assign definite dates to many of the introductions.

In October, 1769, Captain Cook landed at Poverty Bay, and later at Anaura Bay, and at both places Messrs Banks and Solander made collections of native plants. He next stayed a week at Tolaga Bay, and 11 days at Mercury Bay. On 21st November a landing was made some miles up the Thames River, and then six days were spent at the Bay of Islands. On 16th January, 1770, he anchored in Queen Charlotte Sound, and made a stay of three weeks. Again on 27th March he was four days in Admiralty Bay to the west of Queen Charlotte Sound. There is no word in all these landings of his introducing any animals or any seeds, yet it is more than probable that Black Rats (Mus rattus), the common ship's rat, were on board the 'Endeavour,' and that some got ashore. It is also possible that some European seeds may have been accidentally introduced. The voyage was one for exploration only, as far as New Zealand was concerned, and the ships were quite differently equipped on later visits.

In December, 1769, only two months after Cook's arrival, De Surville spent three weeks in the 'Saint Jean Baptiste' in Mongonui Harbour.

In 1772 the French expedition under Marion du Fresne which had such a fatal ending as far as New Zealand was concerned, spent over two months in the Bay of Islands; and it is stated by both Taylor and Polack, I do not know on what authority, that Crow Garlic (Allium vineale), which is so abundant in that district, was introduced by him. No collections of plants were made during either of these French expeditions, but it is quite possible that some animals or plants found their way into the country.

Crozet, who took up the command of the expedition on Captain Marion's death, writes (in 1772):

I formed a garden on Moutouaro Island, in which I sowed the seed of all sorts of vegetables, stones and the pips of our fruits, wheat, millet, maize, and in fact every variety of grain which I had brought from the Cape of Good Hope; everything succeeded admirably, several of the grains sprouted and appeared above ground, and the wheat especially grew with surprising vigour. The garden on Moutouaro Island alone was not sufficient to satisfy my desires. I planted stones and pips wherever I went, in the plains, in the glens, on the slopes, and even on the mountains; I also sowed everywhere a few of the different varieties of grain, and most of the officers did the same.

Captain Cook in his second voyage in the 'Resolution,' spent