PLANT LIFE MARVELS

Evening Post, Volume CXII, Issue 117, 13 November 1926, Page 20

PLANT LIFE MARVELS

LIVING ANTS' NESTS.

A group of English naturalists and travellers were asked by the editor of "Conquest" to write on the subject.. "The Most Bemarkable Plant I Ever Saw." Professor D. Thoday, of University College, Bangor, and formerly of the University of Capetown, tells of mangrove trees which are remarkable in many ways. They inhabit the soft mud of tropical and sub-tropical estuaries, keeping themselves upright by prop roots, which grow obliquely down from trunk or branches; they flourish in sea water, which kills most flowering plants; they possess special breathing organs by which air is supplied to the roots buired in the waterlogged mud; their seeds germinate while still on the tree, and form seedlings which are specially adapted for fixing themselves in the mud when they drop. He continues:—"Rising from the mud are the peculiar breathing organs, formed from knee-like bends of the root above the mud. When these structures are uncovered by the tide their spongy tissues allow air within them to communicate freely with the atmosphere." Dr. Alex. Hill, secretary of the Universities Bureau, contributed the following:—'JWhen in Western Australia, exploring^he beautiful caves at Yallirigup, I exclaimed to my guide: 'That is not a stalactite, it is wood,' and I pointed to a column as thick as my arm, which reached from the roof to the floor. 'It is the root of a jarrah' (Eucalyptus marginata), he replied. 'We are 90ft below the surface, and that root is to be seen in the chamber under this, 30ft lower down.' " Professor M. C. Potter, formerly of the University of Durham, tells of the genus Euphorbia with its extraordinarily varied forms and wonderful structural adaptations. He writes:—"The most remarkable species I have seen is that strange leafless' form E. aphylia. Its clustering rods rise three or-four feet from the bare red soil of the Karroo, where, under a perfectly cloudless sky both day and night, it is exposed to violent extremes of temperature. Its peculiar smooth cylindrical structure exposes a minimum of surface for evaporation of water, and the intense, glistening white colour, by diminishing absorption of heat, affords additional protection from the sun's rays. Its roots penetrate the earth to an enormous depth." Professor R. H. Yapp, of the University of Birmingham, writes that one of the most remarkable plants he has encountered in its wild state is the Malayan fern. He says:—"l first saw this fern on a jungle-covered mountain ridge some 5000 ft above sea level in the interior of the Malay Peninsula. It was growing, as it always does, on the branches of trees. The fleshy, creeping stoms of this curious fern give off numerous branches, which, form thick, black, encrusting masses, often several feet in length, completely encircling the branches of'its host. A system of communicating passages or galleries runs through the entire mass of stems and branches. These galleries are invariably inhabited by colonies of ants, the fern being literally a living ants' nest. The ant galleries have a definite arrangement. Inside each stem or branch, along almost its entire length, is a continuous central passage or corridor. At intervals side passages are given off to other branches, while overhead are two series of separato cavelike galleries, all built to precisely the same pattern. Each overhead gallery communicates by a short passage. This complicated system of galleries is not tunnelled out by the ants, but appears naturally in the fleshy tissues of'the plant. The ants, however, excavate short entrance passages from the exterior, and so find their .way into this ready-made nest. If an inquisitive naturalist interferes with their living house the ants sally forth and pugnaciously attack the intruder. ..- Still more extraordinary cases are known of tho close association of plants and ants. Elaborate though disputed theories have been put forward regarding tho interrelations of theso strange partners."