CELLULAR, ADIPOSE, MUSCULAR TISSUE. 



some parts of the bones, and spongy in others. This tissue 

 is traversed by infinitely ramified conduits, called the canals 

 of Havers, which contain the blood-vessels and the medullary 

 substance or marrow. 



Cartilaginous and fibre-cartilaginous tissue. 



Cellular or connective tissue, more exactly named laminated 

 tissue, formed of laminated fibres, long, flattened, undulated 

 filaments in bundles, and of fibres appertaining to elastic 

 tissue. In nearly every part of the body this substance fills 

 the spaces between the tissues or between the bundles of the 

 fibres of which they are made up : on the surface of the body 

 and of its cavities, and around the organs, it is disposed in 

 enveloping membranes. 



Adipose tissue is formed of cells 

 or vesicles containing fat. It is 

 never found except in the cellular 

 tissue and at the points where this 

 last is least dense. 



These two tissues united are com- 

 monly designated by the term fat, 

 or fatty layer, but they are distinct 

 notwithstanding, and neither wasting 

 nor increase of fat causes any change 

 in the mass of the cellular tissue, but 

 only in the quantity of fat contained ,-,. 



; "_ J _. . Fig. 4. Laminated fibres in the 



111 the Cells Of the adipose tiSSUe. first stage of development. 



Epithelial tissue has for its ana- 

 tomical elements, cells or free nuclei, which form by juxta- 

 position either a very thin single layer, or several superposed 

 layers. It is of this tissue that the epidermis and the 

 epithelium, a kind of internal epidermis, are essentially com- 

 posed. 



Muscular tissue. This constitutes the muscles, or. the 

 flesh, properly speaking. It is composed of elements called 

 muscular fibres, which are of two sorts, the smooth, formed 

 of fibre-cells, and the striped, formed of bundles of fibrils. 

 The fibrils are the fundamental element of the muscular 

 tissue; their primitive microscopic bundles unite in secon- 

 dary bundles visible to the naked eye, and are known in 



