Ch. IX. | LEAVES, eae 
steat Being, who watches with unceasing care over his vast 
creation. ‘To observe the progress of life, whether in the ve- 
_ getable or animal kingdom, is highly interesting to an inves- 
tigating mind;—but here the power of man can achieve 
nothing; he may plant and water, but God alone giveth the 
increase. 
177. A bud lives; am infant lives; both are destined to 
grow and to pass through physical changes; but the bud, 
although active with a principle of life, knows not its own 
existence; while the infant becomes conscious of its own pow- 
ers and faculties, capable of loving those who have con- 
tributed to its well-being, and of adoring the great Author of 
its existence, 
CHAPTER IX. f 
Of Leaves. * 
78. The leaf is generally a thin, flat organ, consisting of 
an expansion of the fibres of the bark, connected by a substance 
which is called the cellular tissue ; the whole is covered with 
a green coat or skin called the cuticle. 
179. Leaves are furnished with pores for exhaling and in- 
haling gases; and as they present to the air a more extended 
‘surface than all other parts of the plant, they are of great utili- 
ee to the vegetable, by imbibing suitable nourishment, and 
throwing off such gases as would be useless or injurious. 
180. We have seen how the bud is formed, and by what cu- 
rious means the principle of vegetable life which it contains is 
_ preserved and protected through the cold and dampness of win- 
fer. In the spring, when the sun has turned his course towards 
the north, re-crossed the equator, and is advancing towards the 
tropic of Cancer,* the vegetable world in our region quickened 
by its stimulating warmth, begins to awaken from its dormant 
state; the leaf-buds expand, and soon bursting their envelopes, 
the green leaves come forth. : 
* It is here presumed that the pupil has been instructed in the appa- 
tent course of the sun, as explained in the common school geographies. 
177. What comparison may be made between a bud and an infant? 
_. 178. What is the leaf? 
179 Etow do leakes inhale and exhale gases ? 
180 When do the leaves usually appear 2 
