77/f; /•7.\A' STHrCTlUE OF Till': iu<h: \\ 



amount, in connective tissue it is usually abundant. Connective 

 tissue is composed of scattered cells, to^f'ther with the inter- 

 cellular substances. The intercellular substances vary according 

 to the service performed by the tissue. 



As an illustration of the binding and connectinR function of 

 this primary tissue study preparations made from materials 

 taken from between the larger nuiscles of the frog. The cells 

 themselves are widely separated by the fibrous intercellular 

 substance which they secrete. These fibers arc of two kinds: 

 (o) fine ones arranged in wavy bundles known as white fibers anil 

 (6) elastic fibers, which are larger, single, and approximately 

 straight in their course. 



Make a drawing of a restricted area to show the characteris- 

 tics of this type of tissue. Label the parts and point out the 

 correlation of intercellular substance and the connecting function. 



Cartilage serves as an example of connective tissue in which 

 the intercellular substance is firm, adapting it for the purpose 

 of meeting the needs of stress, strain, and impact. Examine a 

 prepared section of the cartilaginous portion of the sternum 

 of the frog. Note that it is composed of a non-cellular homo- 

 geneous matrix within which the cells are scattered in rounded 

 spaces or laciuuv. Each cell secretes about it the intercellular 

 substance or matrix. Around the border of the cartilage may be 

 seen a connective tissue layer containing cells, which, as the 

 cartilage increases in mass, become transformed into functioning 

 cartilage cells and surrounded by matrix. Keep in mind that 

 the functional part of cartilage is the matrix. 



Make an enlarged drawing of a small area of cartilage and 

 label the parts. 



Muscular tissue is composed of elongate, contractile cells 

 hound together by connective tissue. Muscle cell and muscle 

 fiber are synonymous terms. The structure of two types of 

 muscles, striated and non-striated, will be studied. 



Striated Muscle. — Other names for this type of muscle may 

 be recalled from the directions on the muscular system, llxatnine 

 a prepared slide of muscle fibers. First locate the nuiterial with 

 the low-power objective and then study it under the high power. 

 The long and relatively narrow elements are portions of muscle 

 cells or fibers, their large size obviating the possibility of securing 

 .sections of a complete cell. The entls therefore appear broken. 

 Every skeletal muscle is composed of a large number of fil)ers or 



