The presence of an additional lower palisade in varieties ofGossypium arboreum andG. herbaceum was confirmed. Except vars. Sujata and PSH, in other varieties ofG. barbadense spongy tissue was thicker than palisade. InG. hirsutum, varieties grown under irrigated and assured rainfall conditions had thicker upper epidermis and the differences in thickness of palisade and spongy tissues per genotype were less than those found in varieties growing under limited supply of moisture. It appeared that greater difference of palisademinus spongy parenchyma inG. hirsutum cottons is a better indicator of drought tolerance than palisade thickness alone or total thickness of the leaf.