24 NORMAL HISTOLOGY. 



ing, at least after death, a reticulated appearance ; 

 this material is called protoplasm in its typical active 

 form, and may be then very soft and viscid, like thin 

 jelly, or it may become so modified as to be hard 

 and even horny like the nail. The cell-body pre- 

 sents a great variety of forms ; it may be spherical, 

 cuboidal, cylindrical, fusiform, ovoid, pear-shaped, 

 discoidal, or scale-like ; it often sends off processes 

 like branches or wings, and sometimes assumes the 

 most irregular bizarre forms. We not infrequently 

 find imbedded in the cell-body, pigment granules, 

 droplets of fat, and various kinds of crystals. The 

 form of the cell-body seems usually to depend largely 

 upon the pressure to which it is or has been subjected 

 by adjacent structures. 



Within the cell-body and making up a part of the 

 protoplasm, we usually find one or more spherical, 

 ovoidal, or irregular-shaped bodies, called nuclei 

 (singular, nucleus]. The nucleus is surrounded by a 

 homogeneous envelope, the nuclear membrane, which 

 encloses the nuclear contents. These consist of two 

 kinds, the formed and the amorphous. The former 

 is composed of threads or fibres which assume the 

 form of a net, intranuclear network, or at times it 

 has the appearance of skeins with numerous twists. 

 This network is suspended in a homogeneous, amor- 

 phous substance, which is believed to be of a fluid 

 nature. The intranuclear network plays an import- 

 ant part in cell division, and its appearance varies 



