For your convenience this file has page breaks disabled. (Tools menu, Display submenu).
You are on the graphics layer. On this layer you can draw graphics and text using the palette shown at the top of this window. To get to the text layer, where you can edit text, click the ruler icon on the top right corner of this window. To get back into graphics, click the icon just below that ruler icon.
Graphics pasted or created here can be moved around and placed anywhere in the text region or the right margin. They automatically attach to the nearest return character (paragraph) just above the top of the graphic rectangle. If this return character is deleted, the graphic is also deleted (but you can Undo!). To see the attachment point of each graphic (as a dotted line) use the “Hilite Variables” command on the Display submenu of the Tools menu. Typing text above the paragraph that contains the graphic will move the graphic with the text. Editing the text within the paragraph to which the graphic is attached, will not move the graphic.
Opaque/Transparent icon shows the opaque graphic with the text line flowing through (under) the graphic, when in the opaque mode or the text lines showing through the graphic, when in the transparent mode.
The icon that looks like this:
is the Opaque/Transparent toggle icon, shown in the opaque mode in which the overlapping graphic covers the graphic underneath. You can change the mode to transparent by clicking the smaller version of this icon (in the graphics palette at the top of this window) with the arrow cursor. If you have more than one graphic and you want some to be opaque and some to be transparent, highlight each independent graphic and click the palette icon changing the mode to be the way you want it. Move the graphic (the Opaque/Transparent icon) shown in this paragraph so that it overlaps the text. You will see that it is not transparent. Now click the Opaque/Transparent icon on the Graphics Ruler to toggle between the two modes.
Flow-through:
The icon that looks like this:
is the Flow-Through/Text Wrapping icon. The text flows through the graphic, ignoring it. Move this graphic across some text in this paragraph to see how it behaves. In this case, part of the text is covered by the graphic, because the graphic is opaque. Notice that moving the graphic around does not change or move the text at all in this mode. To change the mode to wrap-around, click this icon on the Graphics Ruler with the pointer.
• You can experiment with the sample below.
Click on the cactus, and select one of the icons on the Graphics Ruler to see the changes.
PLANTS ADAPTED TO THE DESERT
The cactus is a plant without leaves. In most plants, the leaves are the site of photosynthesis, the "factories" where the sun's energy is used to make food. Why then do cacti and many other desert plants lack leaves?
Though leaves help a plant, they can also do it some harm. Their microscopic openings allow gasses—including water and vapor—to enter and escape. During a single summer day, a large tree may lose several tons of water. Usually, this is not a problem for plants, but in the desert, water loss can be deadly.
For most of the year, the ocotillo, a common North American species, is a thorny bundle of brown, wand-like branches, each about 10 to 20 feet long. Soon after the spring rains—if they come—brilliant red flowers emerge from the end of wands (they give the plant another of its common names—candlewood). Within a few days, leaves emerge from the stems; their small size minimizes water loss. By early summer, the leaves have fallen.
Like the ocotillo, the creosote bush (its Spanish name means "little stinker") has small leaves that remain on the plant for only a short time. But the creosote bush goes the ocotillo one better—in a severe drought, it loses twigs and even branches. In addition, the creosote bush poisons neighboring plants—a substance secreted by its roots kills other seedlings, which might compete with it for water. Creosote bushes often grow evenly spaced, as if they were planted in an orderly fashion by human beings. The spacing is a living record of the climate; the heavier the rains were in the preceding years, the closer together the bushes grow because the moisture washes the root poison deeper into the soil. (Liquid creosote, the familiar wood preservative, is made mainly from coal tar, not from these shrubs.)
Cacti have spines, not leaves. Because the spines have no openings, water loss is not a problem. In addition, the spines are believed to provide some shade for the cacti and to trap and insulating layer of air. And, of course, the spines also serve as a deterrent to plant-eaters.
A cactus's outer skin is a tough, waxy coating that further protects the plant from water loss, almost as if it were covered with plastic wrap. Photosynthesis takes place in the stem of the cactus, which also stores water. Cacti are included in a group of plants called succulents, which are juicy and retain water. The moisture in many succulents takes the form of a gummy sap. (The plant can nevertheless be used as a water supply for thirsty travelers, if the pulpy interior is pulverized.) The sap may dry out if the plant is wounded, creating a plastic-like "bandage" that lessens water loss. Long after a cactus is dead and gone, these cup-like formations—called desert shoes by some Indians—may remain on the desert floor.
