CHAPTER V. 
DEVELOPMENT. 
Progressive changes during growth.—Morphological, physical, and phy 
siological.— Influence of inheritance.—Variation.— Selection.—Re 
serve-materials: their formation and transport. — Germination. — 
Maturation.—Ripening of fruits and seeds. 
Development as here understood includes those pro: 
gressive changes of form and appearance which accom: 
pany the growth of a plant from an infantile to an adull 
state, It forms no part of our present plan to pursue 
this part of the subject here, as any elementary text-book 
contains sufficient details as to the progressive organiza- 
tion of flowering plants. Growth considered separately 
results in increase of bulk only, but development includes 
the whole cycle of changes which convert an atom of 
homogeneous protoplasm into a tree laden with fruit or 
into a wheat plant heavy with golden ears. A mangel ox 
a turnip which, under favorable circumstances, gets big- 
ger and bigger, may be said to grow. It increases in size 
and weight, but neither its outward appearance nor its 
internal construction is otherwise much affected. The 
giant mangels exhibited at root shows illustrate growth 
rather than development. They are very big, but their 
nutritive power is by no means in proportion to their 
size, as the quantity of nutritive matter developed is 
small indeed as compared with the great quantity of 
water they contain. Growth, in fact, is but the prepara- 
tory stage, during which material and machinery are 
acquired, to be turned’ to subsequent use in the consoli- 
dation of the stem, the construction of flower and seed, 
the formation and storage of reserve food-materials, of 
starch, of oil, of the various secretions, such as the 
caoutchouc, the alkaloids, as quinine, morphia, and many 
others. : 
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