This document provides instructions for determining the vein islet number and vein termination number of plant leaves. It defines a vein islet as a small area of green tissue surrounded by veinlets. The procedure involves clearing a leaf sample using chloral hydrate, drawing a 1mm scale using a stage micrometer and camera lucida, and counting the number of vein islets or vein terminations within a 1mm squared area between the midrib and leaf margin. Sample counts are provided for some common plant species like Cassia angustifolia and Digitalis purpurea. The vein termination number is defined as the number of ultimate free terminations of veinlets per square mm of leaf surface midway between the midrib and margin.