Monocotyledons, and Dicotyledons, agrees with that taken from the absence, the existence, and disposition of a vascular system. Hence the peculiarities of the organs of reproduction may be a sufficiently certain index of the structure of those of nutrition ; but as these determine the nature of the secretions or products of plants, so it follows that the properties of plants may be in accordance with their classi- fication into natural families.
But as examples are more convincing than general reason- ing, we may readily refer to numerous instances, to render this conclusive. No one is surprised at hearing that the Graminece of tropical regions are as fitted for food as those of European countries ; or that the oak of the Himalaya yields excellent timber; or that pines abound in turpen- tine, and may be made to yield tar wherever they are found. So the Rosacea afford us our best fruits; among the Papilionacece, are found all the legumes used as food in different parts of the world, and the Labiatce yield most of our odoriferous herbs, as lavender, rosemary, thyme, sage, savory, marjoram, and mint. The Burseracece, a tribe of TerMnthacece, afford resins combined with essen- tial oil ; as we see in the balm of Gilead and Myrrh trees, Balsamodendron gileadense and Myrrha ; B. opobalsa- mum, Kataf and Kalaf, all give out a balsamic odour. Indian Bdellium is probably produced by Balsamodendron Agallocha ; African Bdellium is yielded by another of this family, Heudelotia africana ; Olibanum by Boswellia serrata ; Pistacia Terebinthus and Lentiscus, afford us Chio turpentine and Mastic. The Laurels give us the Camphor of Japan; the Cinnamon of China, as well as that of Ceylon ; Cassia, Sindoc, Calitlawan, the Mala- bathrum leaf in India, and the Bay-leaf in Europe. Of the Dipterocarpece, one species yields the Camphor of Sumatra ; Skorea robusta the resin called ral, but dammer
