【正文】 e of factors: a slow rate of decay of soft tissues, little scavenging by other animals, a lack of swiftcurrents and waves to jumble and carry away small bones, and fairly rapidburial. Given these factors, some areas have bee a treasury ofwellpreserved ichthyosaur fossils.The deposits at Holzmaden, Germany, present an interesting case foranalysis. The ichthyosaur remains are found in black, bituminous marineshales deposited about 190 million years ago. Over the years, thousands of specimens of marine reptiles, fish and invertebrates have been recovered from these rocks. The quality of preservation is outstanding, but what is even more impressive is the number of ichthyosaur fossils containing preserved embryos. Ichthyosaurs with embryos have been reported from 6 different levels of the shale in a small area around Holzmaden, suggesting that a specific site was used by large numbers of 　ichthyosaurs repeatedly over time. The embryos are quite advanced in their physical development。their paddles, for example, are already well formed. One specimen is even preserved in the birth canal. In addition, the shale contains the remains of many newborns that are between 20 and 30 inches long.Why are there so many pregnant females and young at Holzmaden when they are so rare elsewhere? The quality of preservation is almost unmatched and quarry operations have been carried out carefully with an awareness of the value of the fossils. But these factors do not account for the interesting question of how there came to be such a concentration of pregnant ichthyosaurs in a particular place very close to their time of giving birth.15 The Nobel AcademyFor the last 82years, Sweden’s Nobel Academy has decided who will receive the Nobel Prize in 　Literature, thereby determining who will be elevated from the great and the near great to the immortal. But today the Academy is ing under heavy criticism both from the without and from within. Critics contend that the selection of the winners often has less to do with true writing ability than with the peculiar internal politics of the Academy and of Sweden itself. According to Ingmar Bjorksten, the cultural editor for one of the country’s two major newspapers, the prize continues to represent what people call a very Swedish exercise: reflecting Swedish tastes.The Academy has defended itself against such charges of provincialism in its selection by asserting that its physical distance from the great literary capitals of the world actually serves to protect the Academy from outside influences. This may well be true, but critics respond that this very distance may also be responsible for the Academy’s inability to perceive accurately authentic trends in the literary world.　Regardless of concerns over the selection process, however, it seems that the prize will continue to survive both as an indicator of the literaturethat we most highly praise, and as an elusive goal that writers seek. If forno other reason, the prize will continue to be desirable for the financialrewards that acpany it。 not only is the cash prize itself considerable,but it also dramatically increases sales of an author’s books.16. the war between Britain and FranceIn the late eighteenth century, battles raged in almost every corner ofEurope, as well as in the Middle East, South Africa, the West Indies, andLatin America. In reality, however, there was only one major war during this time, the war between Britain and France. All other battles were ancillary to this larger conflict, and were often at least partially related to its antagonist’ goals and strategies. France sought total domination of Europe. This goal was obstructed by British independence and Britain’s efforts throughout the continent to thwart Napoleon。 through treaties. Britain built coalitions (not dissimilar in concept to today’s NATO) guaranteeing British participation in all major European conflicts. These two antagonists were poorly matched, insofar as they had very unequal strengths。 France was predominant on land, Britain at sea. The French knew that, short of defeating the British navy, their only hope of victory was to close all the 　ports of Europe to British ships. Accordingly, France set out to overeBritain by extending its military domination from Moscow t Lisbon, fromJutland to Caldaria. All of this entailed tremendous risk, because Francedid not have the military resources to control this much territory and stillprotect itself and maintain order at home.French strategists calculated that a navy of 150 ships would provide theforce necessary to defeat the British navy. Such a force would give France a threetotwo advantage over Britain. This advantage was deemed necessary because of Britain’s superior sea skills and technology because of Britain ’s superior sea skills and technology, and also because Britain would be fighting a defensive war, allowing it to win with fewer forces. Napoleon never lost substantial impediment to his control of Europe. As his force neared that goal, Napoleon grew increasingly impatient and began planning an immediate attack.17 Evolution of sleepSleep is very ancient. In the electroencephalographic sense we share it with all the primates and almost all the other mammals and birds: it may extend back as far as the reptiles.　There is some evidence that the two types of sleep, dreaming and dreamless, depend on the lifestyle of the animal, and that predators are statisticallymuch more likely to dream than prey, which are in turn much more likely to experience dreamless sleep. In dream sleep, the animal is powerfullyimmobilized and remarkably unresponsive to external stimuli. Dreamless sleep is much shallower, and we have all witnessed cats or dogs cocking their ears to a sound when apparently fast asleep. The fact that deep dream sleep is rare among pray today seems clearly to be a product of natural selection,and it makes s