" A BUNDLE OF TWIGS."

Otago Witness, Issue 2894, 25 August 1909, Page 14

" A BUNDLE OF TWIGS."

NEW ZEALAND BOTANY.

Mr G. M. Thomson, F.L.S., M.P., delivered a lecture in connection with the Maori Hill Presbyterian Literary and Debating Society on Monday, 16th inst., in the church, Maori Hill. The Rev. W. M'Donald presided, and briefly introduced the lecturer, whose subject was entitled "A' Bundle of Twigs," which consisted of specimens of the native fuchsia tree, the com* mon tutu, the rata, and two or three varieties of veronica (koromiko). The building was comfortably full, and the lecturer treated his subject in a non-technical and most interesting manner. Taking a sprig of fuchsia, he showed its very brittle nature, and mentioned that this was one of about three " natives *' which were not evergreens. The reason in this instance, he stated, was its brittle nature, and that the slope of its branches was not altogether up (a peculiarity of the spruce fir) or altogether downward— a characteristic typical of most North American bush. If the fuchsia, therefore, retained its foliage during the winter the weight of the snow would strip the tree of its branches. Another interesting faot which he mentioned was that the nectar of the fuchsia flower attracted the -tuiu and mokis, which unconsciously fertilised the flower. The tree afterwards develops a succulent berry, to which these birds are very partial, and the seeds of this .berry, passing through the digestive tract of the bird without harm, are distributed all over the place. He stated, further, that a fuchsia of the same genus as ours is to be found on the slopes of the Andes, in South America, extending from Tierra del Fuego almost- to Mexico. Tutu, another berry-bearing tree, has a similar distribution, being also found in South America. From these facts, and also from the fact that a species .of earthworm (Nothordrilus) is peculiar to both New Zealand and South America, he deduces that there must have been formerly a very much closer land connection than at present exists. The fact that vast coal beds .have been ' discovered in the supposed continent of Antarctica proves conclusively the existence of vegetation there in former times, and consequently the fact of a very much warmer and, in fact, temperate climate. His theory is, then, that these seeds were conveyed by birds from and t<> New Zealand, via Antarctica and intermediate islands. The rata. of which there are 11 varieties, has a somewhat different distribution, being found, as well as in New Zealand, on the east coast of Australia, iii New Caledonia, and in Melanesia, which, mdi- ' cates the existence of a fairly continuous land connection between these places ages. ago. This theory receives some confirmation from an incident related to Mr Thomv son by an officer engaged in a cable-laying expedition between Brisbane and Auckland. Whilst taking soundings he found that the depth, although considerable in the vicinity of the Australian coast, gradually de- ' creased, and -on one occasion they experienced in the course of a day or thereabouts a rise from a depth of 11,000 ft to 700 ft, proving the existence of a subterranean range of mountains, afterwards discovered to be approximately 80 miles in extent. In the course of ages (and, as the lecturer mentioned, " geologically speaking, a million years here or there is nothing ") this land has probably subsided some thousands of feet, originally being well above sea level, this accounting for the distribution of the rata. The native koromiko (veronica) was next dealt with, the lecturer showing two or three varied specimens, and mentioning how wonderfully it and its sister trees adapted themselves to climatic conditions through the leaves reducing their breathing surface. The fuohsia, for instance, had 140,000 little openings or mouths per squareinch of leaf surface. The reason that they - wither so quickly when subjected to, say, a warm nor'-wester, was that they could not draw up sufficient moisture .to keep pace with the" increased evaporation which occurred. The fact that the veronica, the matakouri, and such-like "natives" had reduced thair breathing surface, and consequently their evaporation, to such an extent (their/ leaves tending to become " woody ") indicated that these islands onceenjoyed a very much warmer climate than they at present do — in fact, something of a " desert " climate. In this connection he mentioned a rather interesting phenomenon — i.e., that when weon the East Coast are 'being' subjected to a warm norVwestor, on the West Coast it will probably be raining " cats and dogs." He illustrated it in this way: Assuminga north-west wind of a temperature of 60degstruck Hokitika, in ascending the mountain chain it would lose, say, lOdeg, causingcondensation and rain on the West Coast. Through discharging this moisture the temperature of the' wind would again rise, say, at least another lOdeg, and, descending the mquntain chain, would gain considerably- * more in temperature, resulting in hot nor'wesfcers, which "take the pith out of the.people of Christchurch." This mountain chain, being originally so much higher above sea level, would naturally cause a corresponding increase in the temperatureof the wind, tending to confirm the theory of the pre-existence here mof a somewhat desert climate Mr Thomson then referred briefly to the necessity of teaching children to use their natural powers of observation. They should be trained not so much fo be letterperfect in such subjects as botany, but toobserve carefully and accurately. In this connection he referred to the technical names- of plants, stating that it was almost as easy, in his opinion,- for an intelligent child to remember a technical name, even though a foot long, as to remember themore vulgar or English name. At the close a hearty vote of thanks was accorded to the lecturer for his interestingand instructive address.