276 BRANSON, ON CILIARY ACTION. 



covered with a complete network of currents. I have ex- 

 amined many varieties of the hairs of plants, and few have 

 been the specimens in which — in some of the hairs at least — 

 indications of currents could not be detected ; so frequently, 

 indeed, have I found these currents, as to lead to the inference 

 that all the hairs of plants are furnished with an apparatus 

 adapted to the production of currents. Now this apparatus 

 is most probably identical with that which ^ives rise to the 

 circulation in the Anacharis, viz., minute cilia. I say most 

 probal)ly, for the extreme minuteness of the currents render 

 the demonstration of cilia in many cases very difficult. In 

 one of the hairs from the leaf of a scarlet Pelargonium a 

 waving current was very evident. In the hairs of the common 

 Primrose a ciliary wave was detected at the edge of the cells ; 

 the waving cun-ent was particularly well seen in this instance, 

 as no granules were floating in the cell, which, when carried 

 along in the current, interfere much with the view of ciliary 

 action, Tlie whole internal surface of the cells of some hairs 

 is probably lined with a minute waving pile. At least this 

 will account for the varied and irregular direction of the 

 currents. In one cell, in the hair of a Polyanthus, 1 watched 

 a flocculent line, or wave, passing diagonally along the whole 

 ot the cell ; the current at the same time setting in the direc- 

 tion of the length of the wave. This is difficult to explain 

 without a diasrram. 



A, arrow indicating the course of tlie wave across tlie cell. B, arrow 

 indicatrng the direction of the current along which floating granules 

 were carried. 



Currents are well seen, not only in the hairs, but also in 

 the cuticle of the leaf of the London Pride ; although the 

 ciliary wave is not well seen in this plant, in consequence of 

 the great number of minute granules which float in the cells. 

 The currents seen in the leaf-cells of the London Pride, and 

 also in the leaf-cells of the Primrose, are precisely similar to 

 those seen in their respective hairs ; they are equally minute, 

 irregular, and weak. Altliough the current is very distinctly 

 seen, the motive force is not sufliciently powerful to move 

 any granules of chlorophyll which may happen to be in the 

 cell ; occasionally, however, a granule of chlorophyll may be 

 seen slowly moved by the current, just as the granules are 



