n the cereal grains, such as Indian
Corn (Fig. 67) and Rice (Fig. 430a), and in all other Grasses, the
embryo is straight and applied to the outside of the abundant albumen.
[Illustration: Fig. 429. Section of seed of Violet; anatropous with
straight axile embryo in the albumen. 430. Section of seed of Rock Rose,
Helianthemum Canadense; orthotropous, with curved embryo in the albumen.
430a. Section of a grain of Rice, lengthwise, showing the embryo outside
the albumen, which forms the principal bulk.]
[Illustration: Fig. 431. Seed of a Chickweed, campylotropous. 432.
Section of same, showing slender embryo coiled around the outside of the
albumen of the kernel.]
392. The matured seed, with embryo ready to germinate and reproduce the
kind, completes the cycle of the vegetable life in a phanerogamous
plant, the account of which began with the seed and seedling.
Section XVI. VEGETABLE LIFE AND WORK.
393. The following simple outlines of the anatomy and physiology of
plants (3) are added to the preceding structural part for the better
preparation of students in descriptive and systematic botany; also to
give to all learners some general idea of the life, growth, intimate
structure, and action of the beings which compose so large a part of
organic nature. Those who would extend and verify the facts and
principles here outlined will use the Physiological Botany of the
"Botanical Text Book," by Professor Goodale, or some similar book.
Sec. 1. ANATOMICAL STRUCTURE AND GROWTH.
394. =Growth= _is the increase of a living thing in size and substance_.
It appears so natural that plants and animals should grow, that one
rarely thinks of it as requiring explanation. It seems enough to say
that a thing is so because it grew so. Growth from the seed, the
germination and development of an embryo into a plantlet, and at length
into a mature plant (as illustrated in Sections II. and III.), can be
followed by ordinary observation. But the embryo is already a miniature
plantlet, sometimes with hardly any visible distinction of parts, but
often one which has already made very considerable growth in the seed.
To investigate the formation and growth of the embryo itself requires
well-trained eyes and hands, and the expert use of a good compound
microscope. So this is beyond the reach of a beginner.
395. Moreover, although observation may show that a seedling, weighing
only two or three grains, may double its bulk and w
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