. Kirkes' handbook of physiology . refore to indicate some of thedifferences between the cells of the body. They are named in various ways,according to their shape, origin, and functions. From their shape, cells are described as spherical or spheroidal, which is thetypical shape of the free cell; this may be altered to polyhedral when the pres-sure on a mass of cells in all directions is nearly the same; of this the primitivesegmentation cells afford an example. The discoid form is seen in blood-corpuscles, and the scale-like form in superficial epithelial cells. Some cellshave a jagged outlin
. Kirkes' handbook of physiology . refore to indicate some of thedifferences between the cells of the body. They are named in various ways,according to their shape, origin, and functions. From their shape, cells are described as spherical or spheroidal, which is thetypical shape of the free cell; this may be altered to polyhedral when the pres-sure on a mass of cells in all directions is nearly the same; of this the primitivesegmentation cells afford an example. The discoid form is seen in blood-corpuscles, and the scale-like form in superficial epithelial cells. Some cellshave a jagged outline and are then called prickle cells. Cells of cylindrical,conical, or prismatic form occur in various places in the body. Such cells maytaper at one or both ends into fine processes, in the former case being caudate,in the latter jusijorm. They may be greatly elongated so as to become fibers. — Remains of spindle. > Lighter substanceof nucleus. S Cell protoplasm. Hilus. Line of divisionof of daughter Fig. 19.—Final Stages of Karyokinesis. In the lower figure the changes are still more ad-vanced than in the upper. (Waldeyer.) Cells with hair-like processes, or cilia, projecting from their free surfaces, area special variety. The cilia vary greatly in size, and may even exceed in lengththe cell itself. Finally, cells may be branched or stellate with long outstandingprocesses. From their junction cells are called secreting, protective, sensitive, contractile,and the like. From their origin ceils are called epiblastic and mesoblastic and hypoblastic(ectodermic, mesodermic, and endodermic). Modes of Cell Connection. Cells are connected together to formtissues in various ways. They are connected by means of a cementing intercellular substance. Thisis probably always present as a transparent, colorless, viscid, albuminoussubstance, even between the closely apposed cells of epithelium; while inthe case of cartilage it forms the main bulk of the tissue,
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