A short review of the theories of crystal growth of perfect and imperfect planeS is given. Experimental evidence of two-dimensional nucleation mechanism of growth of perfect crystal planes is provided for the first time and some crystallographic parameters of this process are determined. A quantitative verification of Frank's theory is given by investigating the growth phenomena on nearly perfect planes. The effect of screw dislocations on crystal growth is studied and some phenomena concerning the influence of surface active impurities on crystal growth and dissolution are reported.