tirwit

[From the cry of the bird.] The lapwing. 'tiş, v. [See def.] A common contraction of it is. ti-san, s. [PTISAN.] IMG:content-1161.png:[blocks in formation] Tiş-ri, s. [Heb. Thishri , from an obsolete root signifying to begin.] Jewish Calendar : The first month of the civil, and the seventh of the ecclesiastical year. It corresponded to part of our September and October. The Great Day of Atonement and the Feast of Tabernacles fell within its limits. Called in 1 Kings viii. 2, Ethanim (=streaming rivers), because the rivers, swelled by the autumnal rains, were then in flood. The name tisri occurs in the Palmyrene inscriptions, and was probably not confined to the Jews. IMG:content-1162.png:[blocks in formation] 1. Histology : A set of cells modified for the performance of a special function; the fabric of which the organs of plants and animals are composed. The structure of ti ues, with very few exceptions, is imperceptible to the una isted eye, and requires the aid of the microscope for its resolution. Tis sues which are absent from plants occur in animals; these are called Animal Ti ues, and have a relation to movement or to sensation, as the muscles and nerves. But plants preserve, protect, and sustain themselves, and the corresponding ti ues in animals are spoken of as the Vegetable Ti ues; of this kind are epithelium and bone. Ti ues always present the same general arrangement in the same organism, but are combined in different ways in different organisms. In the lower forms of life, whether animal or vegetable, the distinctions between ti ues become le and le obvious, and there are organisms so extremely simple that the ti ue of their bodies is of a uniform cellular char acter. (1) Animal : The term ti ue is used in dealing with ( a ) the structure of organs, which are com posed of various ti ues; and (b) specially of the component parts of organs. In the first and wider sense, the anatomical individual is made up of o eous ti ue, or bone; muscular ti ue, or flesh; adipose ti ue, or fat; cartilaginous ti ue, or gristle; connective ti ue, serving to bind the whole together; and pigmentary ti ue, or coloring mat ter. In dealing with animal ti ues in the strict sense, histological analysis shows them to be much more differentiated and elaborate in structure than those of plants. They may be divided into: (a) Epithelium, consisting of nucleated protoplasmic cells, forming continuous ma es, either arranged in a single layer, or stratified and forming several superimposed layers. The lining of the tubes and 4105 alveoli of secreting and excreting glands, and the sensory or terminal parts of the organs of sense consist of epithelium. (b) Connective Ti ue, a name applied to a variety of ti ues developed from the same embryonal element, serving more or le as framework or connecting substance for nervous, muscular. glandular and vascular ti ues. In the embryo and in the growing condition one may be changed into the other, and in the adult they gradually shade off one into the other. These ti ues are divided into three groups, in all of which the ground substance, matrix, or intercellular substance, is distinguished from the cells embedded therein: (i) Fibrous connective ti ue, consisting of microscopic, band-like, or cylindrical bundles of exceedingly fine homogeneous fibrils, sometimes aggregated in groups, and held together by an albuminous, semi-fluid cement substance called globulin. (ii) Cartilage, consisting of a firm ground substance with cells imbedded therein. Cartilage may be Hyaline, having the ground-substance firm and resembling ground-gla ; Fibrous, or FibroCartilage, consisting of fibrous connective ti ue arranged in bundles, and these again in layers; and Yellow, Elastic, or Reticular. having the ground IMG:content-1163.png:[merged small][merged small][ocr errors] A. Animal. Striated muscular ti ue. B. Vegetable. Cellu lar ti ue, composed of prosenchymatous cells. work permeated by dense networks of elastic fibrils. (iii) Bone and Dentine, both developed from transformed embryonal connective ti ue. (c) Muscular ti ue: (i) Non-striated, consisting of nucleated cells, contractile in one definite direction, becoming shorter and thicker during contraction. (ii) Striated, composed of extremely long more or le cylindrical fibers, held together by bundles of fibrous connective ti ue so as to form larger or smaller bundles; these again are aggregated together by stronger bands and septa of fibrous connective ti ue, and these into the fascicles or divisions of an anatomical muscle. (d) Nervous, consisting of bundles of nerve-fibers held together by fibrous connective ti ue, which carries the blood-ve els supplying the nerve trunk, a plexus of lymphatics, groups of fat cells, and sometimes numerous plasma cells. (2) Vegetable : Two forms of aggregations of cells, called generally Cellular Ti ue, may be distinguished, according to the form and relative position of the cells which compose them: ( a ) Parenchyma (Areolar, Utricular, or Vesicular Ti ue), in which thin-walled cells, of a diameter nearly equal in all directions, are united to one another by broad surfaces; and ( b ) Prosenchyma, in which the cells are pointed at both ends, and are much longer than they are broad. When the walls of the cells are much thickened, the ti ue is called sclerenchyma: this may be either parenchymatous or prosenchymatous, according to the form of the cells. When the transverse walls of a row of super-imposed cells are absorbed or perforated, so that they coalesce and form tubes or ve els, the ti ue is said to be vascular. When all the cells have ceased to divide, and have a umed their definite form, the ti ue is called permanent; when, on the contrary, the cells are still dividing, it is called generating ti ue. When several different ti ues occur in one plant, as in all the higher plants, they are arranged into systems. Three such systems of ti ues are usually met with: (1) The epidermal, which covers the exterior of the plant, and usually consists of a single layer of cells; (2) the fibro-vascular, which traverses the body of the plant in the form of bundles, and is characterized by the presence of tubes and ve els, and of long, pointed, prosenchymatous cells-the Wood-fibers; (3) the fundamental ti ue, which fills up the rest of the space, and consists princi pally of parenchyma. 2. Entom .: A European geometer moth, Scotosia dubitata . The fore wings have numerous transverse wavy lines; the larva feeds on buckthorn.