Vital theory:

                  Vital theory supports that the upward movement of water occurs due to the activities of living cells. A few important vital theories are as follows:

a) Pumping activity theory:

                              This theory was given by Godlewaski in 1884. According to this theory, the upward movement of water occurs through the pumping activity of xylem parenchymatous cells. Tracheids and vessels behave as waterreservoirr.

b) Pulsating theory :

                      This theory was given by J.C Boss in 1923. According to him, the upward movement of water occurs due to the pulsating activity of the inner cortical cells present outside the endodermis. According to this theory, the Pulsatory activity of the inner cell absorbs water from the outside and pumps the water into the vessels. 

                                          Both above theories are later discarded because the upward movement of water occurs even through the xylem. Parenchyma cells and inner cortical cells are damaged or killed by the uptake of poison even then the movement of water continuese.