30 
PRINCIPIA 
3d. Scapus (a stalk) is an herbaceous trunk, which ele-? 
vates the fructification, but not the leaves; that is, it is a stalk 
proceeding immediately from the root, and terminated by the 
flowers, as in narcissus , hyacinth , &c. 
4th. Stipes (a trunk) used by Linnaeus for the trunk of 
mushrooms; as also for that slender thread or footstalk which 
elevates the feathery or hairy down, with which some seeds 
are furnished, and connects it with the seed, as in lettuce , 
dandelion , &c. 
III. The LEAVES, which are said by Linnaeus to be the 
muscles or organs of motion of a plant; by others, the organs 
by which perspiration and inspiration are performed. Hence, 
like insects, if the spiracula of the leaves are stopped by 
covering the upper surface with oil, death ensues. They are 
defined as proceeding from the expansion of the vessels of 
the stalk,forming several ramifications like net-work, extended 
in length and breadth in a determinate manner, having the 
interstices filled up with a tender pulpy substance, called the 
parenchyma; and the external covering is supposed to be a 
continuation of the scarf skin of the stalk. 
Leaves are either simple or compound , arid are distin¬ 
guished by their figure, situation, insertion, number, divi¬ 
sions, 8tc. 
A Simple leaf, is such as either adheres to the branch 
singly, or whose footstalk is terminated by a single simple 
expansion, not parted to the middle rib; and is determined, 
by its shape, surface, and divisions. 
A Compound leaf, is such whose footstalk is furnished 
with several separate simple expansions, or in other words, 
whose divisions extend to the middle rib ; now called a com¬ 
mon petiole (or footstalk) supporting several lobes, or little 
simple leaves, of which the compound leaf consists ; and are 
distinguished by shape, &c. and the form by which they are 
attached to the common footstalk, as palmated, winged, 
feathered, &c. Sometimes leaves are twice or more com¬ 
pounded, which divsions admit of many modifications, and 
give rise to as great variety of terms. It may sometimes be 
