. Botany all the year round; a practical text-book for schools. Botany. 92 SEEDS AND SEEDLINGS. 209, 210. — Dissected cotton seed: 209, seed with lint removed (magni- fied three times), f, funiculus, or seed stalk, r, rhaphe, ch, chalaza; 210, cross section of the seed still more highly magnified, showing the crumpled cotyledons. groove on one side, leading from the small end to the big end. Make a sketch of the side showing this line, label it rhaphe, and the point where it begins, at the large end of the seed, chalaza. Look for the hilum at the other end of the rhaphe, and for the micropyle
. Botany all the year round; a practical text-book for schools. Botany. 92 SEEDS AND SEEDLINGS. 209, 210. — Dissected cotton seed: 209, seed with lint removed (magni- fied three times), f, funiculus, or seed stalk, r, rhaphe, ch, chalaza; 210, cross section of the seed still more highly magnified, showing the crumpled cotyledons. groove on one side, leading from the small end to the big end. Make a sketch of the side showing this line, label it rhaphe, and the point where it begins, at the large end of the seed, chalaza. Look for the hilum at the other end of the rhaphe, and for the micropyle near it, at the small end of the seed. If they can not be distinguished on account of the lint, make a longitudinal section of a well-soaked seed and find where the hypocotyl points. Which way did it point in the bean .'' This is the case with all seeds ; the base of the hypocotyl is towards the micropyle, and so we can always tell where the micropyle is by noticing which way the hypocotyl points. Make an enlarged sketch of the section as it appears under the lens, and also of a cross section of another soaked seed about midway between the two ends, showing as accurately as you can the lines of any folds or convolutions that you may see. Label such parts as you can clearly make out, leaving the others till after further examination. From a seed that has been boiled for five or ten minutes to soften the contents, gently remove the coats so as to leave the embryo whole. How many seed coats are there.'' How do they differ in color and texture ? Try to distinguish them in the sketches you have made, and label the hard outer one that corresponds to the shell of an egg, testa, the soft inner one, tegmen. What is the use of each.'' As the coats were removed did they seem to adhere to the kernel more tenaciously at one point than Look for a little dark spot inside near the base, that marks where the seed coats and kernel adhered together. Refer to your sketch of the out-
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1903
