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 
