2 JUNE 1923, Page 21

The Physiology of the Ascent of Sap. By Sir Jagadis

Chunder Bose. (Longmans. 16s. net.) The Physiology of the Ascent of Sap. By Sir Jagadis Chunder Bose. (Longmans. 16s. net.)

Professor Bose here challenges the view, towards which modern botanical opinion seems inclined, that the ascent of water in the plant is due to purely physical forces. A rhythmic series of " pulsations' consisting of alternating expansions and contractions of the living cells, is regarded as the causal agency. Only indirect evidence of these pulsa- tions is offered and other views do not seem to have been sufficiently considered. Incidentally, a number of very cleverly designed pieces of apparatus are described and root-pressure and water-secretion are discussed.