50. Q. What are hairs? A. They are epidermal structures, composed of one or more cells.
51. Q. What do we find next to the epidermis? A. The cortex, or bark, often composed of cells containing starch or chlorophyll.
52. Q. What is beneath the bark? A. The formative layer or cambium, in which thin-walled cells become transformed into vascular or bast-cells, and thence are changed into permanent cells.
53. Q. What do groups of cells thus formed, united into bundles and penetrating the rest of the tissue, form? A. The fibro-vascular bundles.
54. Q. What are the simpler types of plants that have no fibro-vascular bundles, called? A. Cellular plants.
55. Q. What are the rest termed? A. Vascular plants.
56. Q. Of what does the fundamental tissue generally consist? A. Of thin-walled cells containing starch, although other forms of cells may be present.
57. Q. What is the simplest form of individual plant life? A. A particle of living matter inclosed in a membrane or cell-wall.
58. Q. What are plants of this type of structure called? A. Protophytes.