Page:EB1911 - Volume 18.djvu/413

 and South Polynesian islands on the south and south-east, suggests, what in fact is found, a combination of races. In some places the oblique Mongolian eye is noticed, and (together with certain Indo-Chinese customs) there is often a scantiness of beard and general “Malay” look, which increases westwards, and seems to imply relations with the archipelago subsequent to the departure thence of the pure Polynesians. In the Gilberts the traces of Polynesian (Samoan) influences are evident, and are confirmed by tradition. Among the Carolines and the Marshalls darker and more savage communities are found, suggesting a Melanesian element, which is further traceable in the Ebon (Marshall) and other languages.

Each of the four main groups, viz. the Caroline, Marshall, Gilbert and Ladrone (Mariana), from long isolation, has developed ethnological peculiarities of its own. The most advanced folk were the “Chamorros” of the Ladrones, owing to the greater natural resources of the islands, and perhaps more frequent contact with influences from the west; but as a separate people they no longer exist, having been nearly exterminated by the Spaniards in the 17th century. Next in advancement come the Caroline islanders. The general Micronesian type is a well-proportioned rather slightly built figure, with small and regular features; head high and well proportioned, but forehead rather retreating and narrow at the temples; cheek bones and chin slightly prominent; straight black hair, lanker than that of the Polynesians, colour somewhat darker than the Polynesians, the Marshalls being darker and more vigorous than the Carolines, while the Gilbert type, though smaller than the latter, is still darker and coarser. The upper 'class greatly surpasses the common people in physique and intelligence.

MICRONUCLEUS, the smaller nucleus in (q.v.). In fission it divides by mitosis, and in conjugation furnishes the pairing or gametonuclei, by whose reciprocal fusion a zygote-nucleus is formed, which gives rise to the meganuclei and micronuclei of the individuals of the next cycle of fission.

 MICROPEGMATITE, in petrology, a very fine intergrowth of quartz and alkali felspar, occurring as the last product of consolidation in many igneous rocks which contain high or moderately high percentages of silica. It shows the same structure on a minute scale as certain s (q.v.) or coarse granitic veins do on a large scale (see, Pl. 2, figs. 6 and 8); the quartz forms angular patches scattered through a matrix of felspar. In polarized light the separate areas of each mineral extinguish at the same time, and this proves that even though apparently discontinuous they have the same crystalline orientation. The felspar may be considered an irregular crystal of spongy structure, the interstices being filled up by another spongy crystal of quartz. This kind of mineral intergrowth is said to be “graphic,” because the coarsely graphic veins have triangular quartz areas dotted over a felspathic background resembling certain primitive inscriptions. Micropegmatite differs from “graphic granite” only in being so much finer grained that its nature can only be detected with the microscope. The felspar of micropegmatite is usually orthoclase, but sometimes albite, oligoclase or microcline. Occasionally it has crystalline form, and then it has been proved that the quartz