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 a tolerable measure of success; he abstains from an excessive use of simile and metaphor, and his style is concise and simple.

Editio princeps, P. Possinus, 1661; in Bonn ''Corpus Scriptorum Hist. Byz., by E. Meincke (1836), with du Cange’s valuable commentary; Migne, Patrologia Graeca, cxxvii.; see also J. Seger, Byzantinische Historiker des 10. und 11. Jahrhunderts (1888), and C. Krumbacher, Geschichte der byzantinischen Litteratur'' (1897). The estimate of his work in R. Nicolai, Griechische Literaturgeschichte, iii. p. 76 (1878), is too unfavourable.

BRYNMAWR, a market town of Brecknockshire, Wales, 14 m. S.E. of Brecknock and 156 m. from London by rail. Pop. of urban district (1901) 6833. It is on the London & North-Western and Rhymney joint railway connecting Rhymney and Abergavenny, being also a junction for a branch line to Pontypool via Blaenavon, and the terminus of the Great Western line from Newport via Nantyglo. The town owes its origin to the development during the first half of the 19th century of ironworks at the upper ends of the valleys that converge in its neighbourhood, its site being previously known as Waun Helygen (Willow-tree Common). The Nantyglo ironworks afford occupation to large numbers of the inhabitants of Brynmawr. Both coal and iron ore were formerly worked, but the coal is exhausted and the ore unsuitable for modern processes. Brynmawr was formed into an ecclesiastical parish in 1875 out of portions of the civil parishes of Llanelly and Llangattock. In 1894 this was formed into an urban district, which was enlarged in 1900 by the addition of a portion of the parish of Aberystruth in Monmouthshire, the whole being at the same time consolidated into a civil parish.

BRYN MAWR COLLEGE, an institution of advanced learning for women, at Bryn Mawr, Pennsylvania, U.S.A., 5 m. W. of Philadelphia. The site occupies 52 acres and overlooks a broad expanse of rolling country. The buildings are of grey stone in the Jacobean Gothic style, and consist of an administration and lecture hall, a science hall, a library containing in 1908 about 55,000 volumes mostly for special study, a gymnasium, a hospital and six halls of residence. The requirements for matriculation are high; students are required to choose their studies according to the “group system,” which permits them to specialize in two or more subjects; and instruction is given largely by means of lectures. The college is open to “hearers” who are not required to matriculate, to undergraduate matriculated students who are not studying for a degree, to undergraduate matriculated students who are candidates for the degree of B.A., and to graduate students who are candidates for the degree of M.A. or Ph.D. The government rests in a board of thirteen trustees and sixteen directors, all the trustees being members of the board of directors. The president of the college is a trustee and director. The institution was founded by Dr Joseph W. Taylor (1810–1880), a member of the Society of Orthodox Friends, and he provided that the trustees also should be members, but otherwise Bryn Mawr College is non-sectarian. It was incorporated in 1880, and was opened for instruction in 1885. In 1908 it had 419 students.

BRYOPHYTA, the botanical name of the second great subdivision of the vegetable kingdom, which includes the mosses and liverworts. They are all plants of small, often minute, size, and, as the absence of popular names indicates, the different kinds are not commonly recognized. Even the distinction between liverworts and mosses is not clearly made, not only the former but other small plants of higher groups being popularly called mosses. A little careful observation soon shows, however, that the Bryophytes form a well-defined class, including several subordinate groups. Though their study necessarily involves minute observation they possess many features of interest. The adaptations they show to their conditions of life are often very perfect and present interesting analogies with the adaptive characters of the higher plants. They are of great scientific interest not only as representing a special type of life-history and organization, but because in several of the subordinate groups series of forms can be traced, which enable the general course of their evolution to be inferred even in the practical absence of fossil remains of any antiquity.

Bryophytes are very generally distributed over the earth, and those of a single country, such as Britain, afford examples of all the chief natural groups. Sometimes, as is the case with the bog-mosses and some arctic mosses, they may cover considerable tracts. As a rule, however, they occupy a subordinate place in the vegetation, and the different kinds require to be carefully looked for. Covering, as they often do, what would otherwise be bare ground, they are of value in assisting to retain moisture in the soil and in preparing the way for its colonization by higher plants. Although many forms are capable of withstanding periods of drought they succeed best in relatively moist climates and localities. This is shown both by their unequal abundance in different localities of one country and in their scarcity in certain geographical regions as compared with their luxuriance in others.

The external appearance and general organization show great variety. In all mosses and many liverworts (figs. 8, 11) the plant consists of a stem bearing small leaves. In a number of liverworts (figs. 2, 7), on the other hand, it presents no distinction of stem and leaf, but is a flat, dorsiventral body usually closely applied to the substratum on which it grows. This, in contradistinction to the leafy shoot, is termed a thallus. True roots are never present, the plants being attached to the soil by rhizoids, which resemble the root-hairs of higher plants.

The reproductive organs borne by the thallus or plant are called antheridia and archegonia, and serve for sexual reproduction. The antheridium (figs. 5, 15) has a longer or shorter stalk and consists of a wall formed of a single layer of flat cells enclosing a mass of minute cells from which the spermatozoids are developed. In the cases which have been most carefully investigated two spermatozoids have been found to arise from each of the small cubical cells of the central tissue. When mature the antheridium opens on being moistened and the spermatozoids become free in the water by the dissolution of the mucilaginous cell-walls enclosing them. Each has the form (fig. 5, D) of a more or less spirally twisted, club-shaped body, bearing at the pointed anterior end two long cilia by means of which it moves through the water. The archegonium (fig. 1) has the form of a narrow flask with a long neck. It usually has a short stalk and consists of a central row of cells enclosed by a layer of cells forming the wall. The egg-cell or ovum lies within the wider basal region or venter, and above it come the ventral canal-cell and canal-cells within the neck of the archegonium. When the archegonium opens by the separation of the cells at the tip, the disorganized canal-cells escape, leaving a narrow tubular passage leading down to the ovum. Each antheridium or archegonium arises from a single cell, and while the mature structure is similar in the two groups, the development presents differences in liverworts and mosses. Without entering into details it may be mentioned that in the mosses it proceeds both in the archegonium and antheridium by the segmentation of an apical cell, while this is not the case in the liverworts. Fertilization is effected by the passage of a spermatozoid, attracted probably by means of a chemical stimulus, down the passage of the archegonial neck and its fusion with the ovum. It thus, as in other cases of sexual reproduction, involves the union of