QUARTERLY CHRONICLE. 141 
state of cohesion, will be drawn out by the mechanical action 
of the rotating mantle-fluid into long filaments or cords, 
either simple or branched, and either terminating in free 
extremities or uniting again in circular or elliptical forms, and 
converted by the co-operation of adhesion into a more or less 
complicated net, diffused between the cellulose capsule and 
the cell-juice. ‘This is the arrangement and configuration of 
the viscid substance in the cells of plants with a so-called 
circulating or circulo-rotating current ; and this is the founda- 
tion of the so-called “ protoplasmic currents”’ so often spoken 
of. When the viscid substance is thus arranged, the free- 
swimming granules very easily get into the domain of its 
fibres and cords, and may easily disappear entirely from the 
open region of the mantle-fluid, and in the struggle between 
the influences of the rotating mantle-fluid and of adhesion 
perform such vacillating and leaping movements as to remind 
one of the so-called ,‘ granular movement” of contractile 
substances. Lastly, in this arrangement the viscid substance 
may be set in motion in the region of its fibres and cords, as 
is proved by the progression on the fibres of swellings with 
imbedded granules or crystals ; but the tenacity of the sub- 
stance may be so considerable, and the power of the rotating 
fluid so small, that such a movement either does not take 
place at all, or not through the whole extent of the net (E. 
Bricke). 
11. The structure of the ramified and net-like configuration 
of the viscid substance depends chiefly upon the degree of 
force of the rotating mantle-fluid, the form of the cellulose 
capsule, the point of attachment of the viscid mass on the 
cellulose capsule, and its relative position to the axis of reta- 
tion of the mantle-fluid, and, lastly, upon its state of cohesion. 
12. There is no essential difference between the rotating, 
circulating, and rotato-circulating currents of the cells; in all, 
the rotating mantle-fluid is to be placed in the foreground ; 
in it alone we can recognise the direct influence of the 
unknown causes of the currents, and this everywhere acts in 
the same way. 
13. The other constituents of the “‘ mantle-layer ” exposed 
to the mechanical influence of the rotating mantle-fluid cause 
the current of the vegetable cell to vary in outward appear- 
ance; they will also, of course, present varying obstacles to 
it according to circumstances. Among the phenomena of this 
nature I may indicate that in the cavities formed between the 
resting masses of the viscid substance the rotating mantle- 
fluid may come to perfect rest, and that then molecular move- 
ments of free granules are detected in such cavities,—further, 
