Page:Popular Science Monthly Volume 21.djvu/308

296 (Fig. 9). The hairs on the young leaves of violets and on common red clover exhibit the same sort of a stream moving in much the same way (Figs. 10 and 11).

The unicellular hairs of the common morning-glory present a different phase of the same current. Here the stream is confined to the



cell-wall most closely, but the movement is unique. The protoplasm in its course is by turns contracted and expanded, giving to the whole current a billowy appearance, a miniature profile of rolling waters. Wave follows wave, but with no deceptive motion, for the rapidly passing granules advise us that the current is strong and real underneath waves that rise and fall but never break (Fig. 12).