Morphic Strata
in geology, the term-first proposed by Lyell in 1833, and since universally adopted for the stratified crystalline rocks-that is, rocks which have been presumably laid down originally by the action of water, and then transformed by fire, chemical agency, pressure, or all combined. Metamorphic action is divided into local-affecting only small portions of rock, or small areas, and regional-affecting rocks over considerable regions. The metamorphic rocks constitute one of the five great classes of rocks. The chief are gneiss, eurite, hornblende schist, serpentine, actinolite schist, mica-schist or micaceous schist, clay slate, argillaceous schist or argillite, chlorite schist, schist, quartzite or quartz rock, and crystalline or metamorphic limestone. Besides these which were probably the first sedimentary, the other classes of rocks have in places undergone metamorphosis.
METAMORPHOSIS (-morfo-sis), a change or transformation in the form, shape, structure, or character of anything.
In botany, a change, especially of an abnormal character, in an organ. It may be progressive or retrogressive. Calyx, corolla, stamens, and pistils are all transformed leaves. In entomology, it means a series of transformations which insects undergo in their progress from the egg to full maturity. There are analogous changes that are more or less co complete in the other orders.
In zoölogy, metamorphosis takes place in many other animals besides insects.
Thus a barnacle (Lepas) or an acornshell (Balanus) is at first a free and swimming creature, which ultimately becomes sedentary and attached to rocks or ships' bottoms. Metamorphosis exists also in Annelids, in Mollusks, in Medusas, etc.
METCHNIKOFF