vii BONK 59 



case with some ligaments of the spine, and particularly so in 

 gra/ing animals. 



When connective tissue, tendons, or ligaments are boiled, 

 the mate-rial forming the white fibrillai is converted into 

 gelatin, a substance somewhat like a proteid, solutions of 

 which have the property of setting into a jelly when cold. All 

 animal jellies are obtained from some form of connective tissue. 



Fatty Tissue. Connective tissue often contains much fat. 

 Sin li tissue is called fatty tissue or adipose tissue. The fat 

 exists in fat cells which are really large modified connective- 

 tissue cells. The fat is first deposited in the form of minute 

 globules in the cell substance of the connective tissue cell, and 

 these minute globules gradually increase in size and run 

 together, forming a single globule of fat which remains covered 

 by a thin layer of the cell substance of the cell. 



Fatty tissue occurs chiefly just under the skin, and in other 

 places filling up inequalities. It gives roundness to the 

 limbs. Its important service is to act as a store of nutriment 

 for the body. 



Bone 



Clear one or two long bones, femur or humerus, of a rabbit, 

 sheep, or pig, free from muscles and tendons, and examine 

 them either at once or after treating them as directed below. 



A Fresh Bone. A bone such as a long bone is covered, 

 except at the ends tipped with cartilage and lying within the 

 joints, by a vascular membrane, the periosteum. The perios- 

 teum consists of fibrous connective tissue, rich in blood-vessels. 

 The periosteum, which is closely adherent to the bone, may be 

 removed by scraping, and the bone itself is then seen to be 

 reddish in colour ; it also is vascular. On the surface, 

 especially near the ends, there are numerous minute holes, by 

 means of which small blood-vessels from the jjeriosteum pass 

 into the bone. Near the middle of the shaft is an aperture, 

 the hole through which the main artery and vein pass to and 

 from the inside of the bone from and to the large artery and 

 vein running in the limb. 



If the bone be sawn across the middle of the shaft it will be 



