OP VITAL MOTION. 13 



through the textures generally, like a stream through 

 a porous rock, and not in fixed and definite channels. 



The movement of the elaborated sap or latex in the 

 laticiferous vessels, to which the name of cydosis is 

 given, has been fully investigated by Professor Schultz. 

 It is the counterpart of the capillary circulation in the 

 higher animals in the earlier periods of their foetal 

 history, or of that which remains permanently in some 

 of the rudimentary entozoid forms ; that is to say, it 

 is not a single and constant stream, proceeding and 

 returning to and from a common fixed centre or heart, 

 but a complex movement, consisting of many distinct 

 currents directed to and from certain independent 

 centres, the positions of which are subject to continual 

 change. This is the plan observable in the vascular 

 area of animal bodies prior to the formation of the 

 heart, and therefore there is nothing special and 

 peculiar in the phenomena of cyclosis. 



The second special movement of the sap, or rotation, 

 is that which is observed in the contents of certain 

 cells, and the phenomena are always limited to one of 

 these rudimentary bodies. The law is not constant, 

 and there are great and manifest variations, not only 

 in different plants, but even in contiguous cells of the 

 same plant. In one instance, the movement is directed 

 along one wall of the cavity, and in a contrary direc- 

 tion down the other side, the line of the current being 

 in accordance with the longitudinal axis of the cell : 



