Key points are not available for this paper at this time.
The motions observable in cells include cytoplasmic streaming (Corti 1774), Brownian motion (Brown 1828), saltatory motion (Taylor 1958, 1964; Rebhun 1964), and axonal transport in neurons (Burdwood 1965; Lasek 1967). All of these except Brownian motion can be characterized as intracellular motility, since metabolic energy is expended. Brownian motion is the result of thermal agitation.
Allen et al. (1982) studied this question.