branchlets produce a head. This is cylindrical, about 5 mm. long, and contained by an involucre of three series of bracts. The florets are about eight in number, the outer ones pistillate, the inner hermaphrodite. All are tubular. The pappus-hairs are long, almost equalling the corolla. The fruit is an oblong cypsela, slightly hairy. The flowers are very sweetly scented, and the scent given off from a large mat area is very noticeable. (γ.) Mode of Growth of Mat. The seedling is at first erect and unbranched. The tap-root is long in proportion to the size of the plant, and the leaves are very broad and hairy. As growth proceeds, branches appear in the axils of the leaves, which rapidly elongate, but their growth is obliquely upwards. Subsidiary branches are given off, which are more horizontal than the primary laterals. Soon the proximal portions of the lowest branches come to rest on the ground, owing possibly in part to root-shrinkage. As growth and branching proceed, more and more branches come to lie on the ground, until a disc of radiating stems is formed round the central root. As this centrifugal growth goes on, adventitious roots are given off from the ventral surfaces of the horizontal stems. Vertical branches are also given off, which end in the branchlets. All the horizontal branches have ascending tips. Occasionally one side of the mat may grow faster than another, but in most cases there is a growth of practically uniform rate all round the periphery. Mats often spread over large boulders, though the extending branchlets seem to prefer running round a stone to running over it. When branchlets come to a tussock they run up through it and become erect. (δ) Epharmonic Variations.* In my usage of the term “epharmonic” I have followed L. Cockayne, whose most recent definition (in Cockayne and Foweraker, 1916, p. 169, as footnote) is as follows: “The term ‘epharmonic’ is here used as in my former writings—e.g., ‘Observations concerning Evolution, derived from Ecological Studies in New Zealand’ (Trans. N.Z. Inst., vol. 44 (1912), pp. 13–30)—with a somewhat different significance to that of Vesque and Warming (see ‘Oecology of Plants’ (1909), pp. 2 and 369). According to my usage, an epharmonic variation is a change in its form or physiological behaviour beneficial to an organism evoked by the operation of some environmental stimulus. Such a change may be called an epharmonic adaptation, as distinguished from such adaptations as cannot be traced to any direct action of the environment. To the neo-Darwinian no permanent adaptation according to the above definition would be ‘epharmonic,’ whereas to the neo-Lamarckian all would be so considered.” The growth-form and morphology given above are those taken from what may be called the “typical” form, but very many variants of the “type” occur. As regards the growth-form itself, there is not much departure from the usual type. The chief variations occur in the branchlets and leaves, and may be arranged thus. (i) As in the typical form, but very hairy, so that the general appearance is grey, (ii) a form with much broader leaves and laxer growth, though not hairy, (iii) a broad-leaved hairy form. (ε) Growth Experiments. Plants of different types were taken from their habitat in March and planted in sandy soil in an unheated greenhouse at sea-level. They were abundantly supplied with moisture. The results were (i) No change in colour during the winter—i.e., no production of anthocyan; (ii) very rapid