The large, conspicuous seed of the avocado is made up of two fleshy cotyledons and a centrally attached plumule, hypocotyl and radicle, the whole surrounded by two papery seed coats closely adherent to each other. There is no endosperm left in the seed at maturity. The outer layer of the outer seed coat consists of one to five layers of stone cells which are irregular in shape with heavy, deeply pitted, lignified walls. A suberin layer occurs at the middle lamella (Pigs. 7, 8). Underlying the stone cells is a layer of large, highly irregular cells which are filled with tannin (Fig. 9). A typical cell measures 118 by 302 microns. Underneath these are several layers of small parenchyma сells of the same general irregular shape as the larger tannin-filled cells next to them. A few oil-bearing cells similar to the idioblasts of the fruit are distributed among these smaller parenchyma cells.