. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. 72 BOTANY Push back the husk of a young ear of corn. The husk is simply a covering of leaflike parts which has grown over the young fruits for their better protection. We have already noticed such a structure forming the capsule of the acorn and bur of chestnut. What did we call it ? We uncover what was a short time before a bunch of ver}^ peculiar flowers. The corn cob is the much-thickened flower stalk on which the flowers were clustered. If you have removed the husk carefully you will se
. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. 72 BOTANY Push back the husk of a young ear of corn. The husk is simply a covering of leaflike parts which has grown over the young fruits for their better protection. We have already noticed such a structure forming the capsule of the acorn and bur of chestnut. What did we call it ? We uncover what was a short time before a bunch of ver}^ peculiar flowers. The corn cob is the much-thickened flower stalk on which the flowers were clustered. If you have removed the husk carefully you will see part of each flower remaining attached to each grain of corn. The so-called silk of corn is nothing more than a long central style and stigma. The corn grain itself was also part of the flower — the same part that formed the pod of the bean with its contained seeds. The corn grain, therefore, is a fruit and not a seed. Is the grain of corn homologous with the pea or bean? Laboratory Suggestions for Work on Grain of Corn? — In a single grain of corn which has been soaked at least twenty-four hours, notice the differ- ences between the attached and free ends of the grain. Look for the scar which marked the at- tachment of the silk. The light-colored area found on one surface marks the position of the embryo; the rest of the grain contains the endo- sperm. Cut a grain perpendicular to the flat side of the grain in a lengthwise direction. Find the embryo from its relation to the outside of the grain. Apply a drop of weak iodine solution. What material is found in the endosperm of corn ? The part of the grain that does not stain so deeply with iodine is the embryo. Find two parts, — a tiny elongated structure and an area lying be- tween it and the endosperm. The latter is the single cotyledon. Use a lens. Notice that the elongated struc- ture in the embryo has two parts, the hypocotyl pointing toward the attached end and the plumule or the epicotyl point- ing toward the unat
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