67. Q. How are Fungi regarded by some scientists? A. As neither animal nor vegetable, but forming a sort of third kingdom.
68. Q. What seems to be the principal business of the Fungi? A. The removal of the waste material of both animal and vegetable life.
69. Q. What are Acrogens? A. Plants which grow at the summit only, and not in diameter.
70. Q. What plants do we find in fresh-water ponds and rivers, growing in tangled masses of dull green color that illustrate the manner of growth in the type of Acrogens? A. Stone-worts, consisting of two genera, Chara and Nitella.
71. Q. What are the nodes, and what the internodes in the stone-worts? A. The points on the axis, or stem, from which the branchlets spring, are called nodes, and the intervening parts are internodes.
72. Q. How is each internode formed? A. By the growth and elongation of single cells.
73. Q. How are the branchlets produced? A. By the sub-division of single cells.
74. Q. What other families of plants are examples of Acrogens? A. Ferns and Mosses.
75. Q. What are Endogens? A. Plants whose vessels and woody fibers first grow within the stem. The seed has but a single lobe, or cotyledon.
76. Q. What families of plants are found in the type of Endogens? A. Grasses, Rushes, Lilies, and Palms, with similar families.
77. Q. In the growing plant what part grows from the axis upward, and what part from the axis downward? A. The stem grows from the axis upward, and the root downward.
78. Q. What is the root formed by the downward elongation of the axis called? A. It is called the primary root.
79. Q. What is the stem of a plant? A. That part which bears the leaves, flowers, and fruit.
80. Q. What is the length of life of the stem and roots? A. It may be only a single year, or annual; two years, or biennial; or a number of years, or perennial.
81. Q. What are thorns? A. Undeveloped branches, and many plants which are thorny when wild are not so under cultivation.
82. Q. Of what are leaves constituted? A. Cells, with cavities, fibro-vascular bundles and epidermis.
83. Q. How do the veins in the leaves of Endogens differ from those in the leaves of Exogens? A. They are generally parallel or straight in Endogens, and do not form a network as in Exogens.