THE MODE OF ORIGIN OF VEIN‐ENDINGS IN THE LEAF OF <i>LIRIODENDRON TULIPIFERA</i> L.

Abstract

S ummary In a study of the development of the reticulate venation of the leaf of Liriodendron tulipifera L. the mode of origin of the vein‐endings receives particular attention. At an early stage in development the veins form a network with very few free ends. Increase in area of the lamina by cell enlargement is accompanied by expansion of the vein system. Its weaker components which are not capable of extending at the same rate as the lamina become broken or disconnected and produce the abundant blindly ending veinlets characteristic of the mature leaf. The pattern of development thus agrees with that already described for Cercis and Primus and probably occurs generally in dicotyledon leaves with reticulate venation.