CALIFORNIA COLLEfii 



^ CELLS 1 5 



(5) Osseous Tissue. A special form of connective 

 tissue, in which enough lime is mixed to make it stiff, is 

 called bony or osseous tissue. This tissue is rigid and 

 strong so as to form a framework for the rest of the cells 

 of the body. A somewhat similar tissue, containing little 

 or no lime, is called cartilaginous tissue. It surrounds the 

 jointed ends of bones and often becomes bone late in life. 



(6) Adipose Tissue. Some connective tissue cells are 

 arranged in microscopic pockets filled with oil or fat. 

 This forms fatty or adipose tissue. Most of the fat in 

 the body is stored in this way (see p. 25). 



10. The blood as a tissue. Blood contains two kinds of 

 cells, each of which has a special work to do. Therefore 

 the blood may be called a tissue, even though its cells are 

 floating free in a liquid. The lymph, which is mainly 

 diluted blood, may also be considered a tissue. 



11. Other fluids in the body. There are other fluids in 

 the body which, while they contain a few cells, do not 

 depend upon them for their properties or actions and so 

 are not tissues. Into the digestive tube there are poured 

 five fluids concerned in digestion, viz. : the saliva, the 

 gastric juice, the pancreatic juice, the bile, and the intes- 

 tinal juice. In order to carry off the waste products of 

 the body two fluids, the perspiration and the urine, are 

 continually being formed, while water is given off in 

 gaseous form by the breath. Three fluids are found in 

 connection with the eye. Two, .called the aqueous and 

 the vitreous humors, distend the eyeball, and another, 

 called tears, runs over its surface to wash away dirt. In- 

 side the cavity of each joint is a thick fluid, called synovia, 

 which lubricates the surface of the bones within the mov- 

 able joints. Lastly, milk is sometimes produced for the 

 nourishment of the young. 



