PINES 281 
506. Germination of the seed takes place when water 
is again supplied, resulting in a resumption of the growth 
of the embryo, the bursting of the brittle 
integument (indusium) and the escape of 
the root, stem and leaves of the embryo. 
The root penetrates the soil and provides 
water, while the leaves (now green) pro- a 
vide carbohydrates, completing the estab- 
lishment of the new plant. Fre. 158.— 
Pinus (seeds, and 
507. There are about half a dozen genera young sporoe- 
of Modern Pines, distinguished by their ?>***’ 
leaves and cones, as follows: 
I. Twigs with primary green 
leaves only. 
1. Cone scales persistent. 
i. Leaves prismatic, four- 
angled. (Spruces) Prcea 
ii. Leaves flat: — 
(a) Megasporophylls (False 
long, protruding. Hemlocks) PsrupotsuGA 
(6) Megasporophylls 
short, not protrud- 
ing. (Hemlocks) Tsuca 
2. Cone scales deciduous, the 
cone falling to pieces. (Firs) ABIES 
II. Twigs with both primary and 
secondary green leaves. 
1. Leaves evergreen. (Cedars) Crprus 
2. Leaves deciduous. (Larches) Larrx 
III. Twigs with only secondary 
green leaves. (Pines) PINUS 
508. The very young twigs of the last genus (Pinus) are 
covered with flat primary leaves which die immediately, 
and in their axils short twiglets push out bearing five, 
three or two very narrow leaves, the secondary leaves, 
which are the only ones persistent on these plants. Com- 
