author - "William Thomas Councilman"

ase of many animals itseems as though the necessity of a fluid environment for living matterdid not apply, for the superficial cells of the skin have no fluidaround them; these cells, however, are dead, and serve merely amechanical or protective purpose. All the living cells of the skin andall the cells beneath this have fluid around them.Living matter occurs always in the form of small masses called"cells," which are the living units. The cells vary in form, structureand size, some