STRUCTURAL COMPOSITION OF THE BODY. 17 



CLASSIFICATION OF TISSUES. 



I. Homogeneous Substance, a more or less solid, albuminous struc- 

 ture, filling the spaces between the cells and fibres of various tissues, e. g. t 

 cartilage, bone, dentine, etc. 



II. Limiting Membrane, a thin, homogeneous membrane, structureless, 

 composed of coagulated albumen, and often not more than the 2 wo^ f an 

 inch in thickness, found lining the blood vessels and lymphatics, forming 

 the basement membrane of the skin and mucous membranes, the posterior 

 layer of the cornea, the capsule of the crystalline lens, etc. 



III. Simple fibrous or filamentous tissue the elements of which 

 are real or apparent filaments. 



(a) Connective or areolar ; white fibrous tissue ; constituting tendons, 

 ligaments, aponeuroses, periosteum, dura mater, synovial membranes, 

 vascular tunics, etc. 



(b) Yellow elastic tissue, found in the middle coats of arteries, veins, 

 lymphatics, ligamentum nuchse, vocal cords, ligamenta subflava, etc. 



IV. Compound membranes (membrano- cellular or fibro- cellular 

 tissues), cells aggregated into laminae. 



(a) Epidermic tissue ; (b) epithelial tissue; (c) glandular tissue ; (d) 

 cornea. 



V. Cells containing coloring matter, or pigment cells, e. g., skin, 

 choroid membrane, etc. 



VI. Cells coalesced or consolidated by internal deposits, e. g., 

 hair, nails, bone, teeth, etc. 



VII. Cells imbedded in an intercellular substance, e. g., cartilage, 

 crystalline lens, etc. 



VIII. Cells aggregated in clusters, forming tissues more or less solid, 

 e.g., adipose tissue, lymphatic glands. 



IX. Cells imbedded in a matrix of capillaries, e. g., gray or vesicular 

 nervous matter. 



X. Cells whose coalesced cavities form tubes containing liquids or 

 secondary solid deposits, e. g., vascular tissue, dentine. 



XI. Cells free, isolated, or floating fluid tissue e.g., red and white 

 blood corpuscles, lymph and chyle corpuscles. 



