Transpiration is loss of water by the plant by evaporation, chiefly from the minute pores or stomata on the leaves.
The importance of transpiration, is, however, so great, that these risks must be run.
Good ventilation is indispensable to allow the worm to give out by transpiration the great quantity of water that it absorbs with the leaf.
The leaves of the plant regulate the amount of water they hold through transpiration.
This arrangement is a method of checking transpiration by creating a still atmosphere above the pore of the stoma, so that water vapour collects in it and diminishes the further outflow of vapour.