H 



PHYSIOLOGY AND MORPHOLOGY OF ANIMALS. 



taneous connective. It is so loose a mesh that water or 

 air may be pumped in so as to swell up the whole body. 

 General dropsy, in fact, arises from accumulation of 

 water in this tissue. When the skin is removed we may 

 dissect between and separate the several muscles. In 

 doing so we cut the connective between the muscles. 

 The same tissue in a denser form constitutes the invest- 

 ing membrane of the muscle. If we cut into the muscle 

 we find that every fiber is invested by the membranous 

 form, and separated from its neighbor fiber by the mesh 

 form of the same. In brief, we may say that this 

 tissue in its denser form invests every fiber, and in its 

 loose form separates and yet connects the fibers; then 

 it emerges on the surface of the muscle in denser form, 

 investing and individuating it; 

 and finally in loose form lies be- 

 tween the muscles, separating and 

 yet connecting them. The same 

 is true of all the organs of the 

 body. 



Varieties. — The loose, meshlike 

 form is called areolar tissue, or 

 sometimes cellular tissue. The 

 denser form is called fibrous tissue. 

 By a little stretch of our defini- 

 tion, the skin, which consists of 

 closely felted, interlacing fibers, 

 may be regarded as an extreme 

 variety of connective. It is called 

 dermoid tissue. Scattered about 

 among the interlacing fibers, es- 

 pecially of the areolar variety, are found nucleated, 

 spindle-shaped cells with branching fibers — connective-tissue 

 cells. Also, the same variety is usually the place of de- 

 posit of so-called fat cells, which accumulate often in 



Fig. 5. — Connective tissue 

 with fat cells. 



