.... is that the latter tends to be an internal hallucinatory-like experience disconnected from the external world. Many dreams collected in laboratories are rather common, but some people tend to experience some bizarre dreams. Early in the 20th century, Sigmund Freud believed that dream content was composed of the mental processes different from that used in the awake state. He believed this was what dominated the dreaming mind. He described this "process" as characterized by more primitive mechanisms, by rapid shifts in energy and emotion, and by a grea .....

.... on the ground, penguins appear myopic, inefficient and generally out of place. In fact the reverse is true. During a recent stay on the Falkland Islands, a Canadian researcher discovered that penguins are able to recognize individuals and navigate the rocky terrain on which they live quite well. Long of body and short of leg, they probably poke their heads forward as an aid to balance. And as for looking at the ground, they're merely-like us-keeping an eye on where they're going. The human eye is adapted for aerial vision, which is why scuba divers-or even .....

.... Doctors estimate that each year 50 out of every 100,000 Americans have mononucleosis symptoms. Among college students, the rate is several times higher. Mononucleosis does not occur in any particular "season," although authorities in colleges and schools, where the disease has been well studied, report that they see most patients in the fall and early spring. Epidemics do not occur, but doctors have reported clustering of cases. Transmission: EBV, the virus that causes most cases of mononucleosis, infects and reproduces in the salivary glands. It also infects wh .....

.... a path near the earth, and they are actually called, "near-earth" asteroids. About 10 percent are bound to hit earth eventually. Asteroids ranging from fine dust, to house size rocks make up the belt around Saturn, and the belt on the outside of the orbit of Mars. These are pieces of larger rocks that were crashed into the remaining pieces after millions of years of crashes. Each ring system has distinctive features. Jupiter's rings are tenuous and made mainly of dark particles the size of those in cigarette smoke. The bright rings of Saturn are made of mainl .....

.... found in east Texas were about 2.5 cm round, from 25 cm to 1.5 m long, and not more than 20 cm below the surface. Each burrow has a large area at the end for the nest which was composed of shredded grass. These nests were used for young or as a resting place for groups of adult shrews. Compared to most types of shrews, the least shrew is sociable, and several may be kept together in captivity without conflict. They sleep together and help eachother to some degree in digging tunnels and finding food. One nest found in December in Texas contained a dozen shrews t .....

.... it occurs in a variety of forms differing in hereditary traits, that are passed from parent to offspring. By chance, some varieties prove to be ill adapted to their current environment and thus disappear, whereas others prove to be adaptive, and their numbers increase. The elimination of the unfit, or the "survival of the fittest," is known as Natural Selection because it is nature that discards or favors a particular being. Evolution takes place only when natural selection operates on apopulation of organisms containing diverse inheritable forms. HISTORY .....

.... or incorporated into the cell membrane. The membranes of the ER usually form a tightly packed and flattened sac-like structures, that form inter-connected compartments within the cytoplasm. The internal space formed by the membrane sheets is known as the ER lumen. In most cells the ER lumen forms a single internal compartment. The membranes of other organelles are not connected to the ER and appear to form separate distinct compartments within the cytoplasm. The ER membranes and lumen contain a large number and variety of enzymes which catalyse many differe .....

.... Nitrogen at 2.7%; Argon at 1.6%; Oxygen at 0.13%; Water at 0.03%; and Neon at 0.00025 %. Martian air contains only about 1/1,000 as much water as our air, but even this small amount can condense out, forming clouds that rise high in the atmosphere or swirl around the slopes of towering volcanoes. Local patches of early morning fog can form in valleys. At the Viking Lander 2 site, a thin layer of water frost covered the ground each winter. There is evidence that in the past a denser Martian atmosphere may have allowed water to flow on the planet. Physical .....