Show transpiration of sap the leaves gives out not only the oxygen derived from the decomposition or of carbonic acid gas taken from the a air ir and carbonic acid gas produced due e d in breathing but also gre great at quantities of water vapor says gifford pinchot in a government bulletin the amount ot of water taken take up by the roots Is very much larger tha than a la Is required to bo be combined with carbon i and the earthy constituents in the leaves in order that fresh supplies ot of earthy constituents in solution may reach the leaves rapidly the water already in them must bo be got out ot or the way this Is effected by transpiration which Is the evaporation ot of water irom from all parts ot of the tree above 1 ground but principally from the tha loaves leaves even here bero the hark bark la Is very thick as on the trunks ot of old oaks and chestnuts transpiration goes on through the lenti cels in the bottoms ot of the deep crack it sometimes happens especially in spring el ring before the leaves come out that transpiration can not get rid ot of the water from the roots as fast as it rises and that it tails falls in drops from the buds or later on oil even from the leaves themselves |