James Blish - A Case of Conscience

The grasses are more prevalent on the plains, shading into rushes and similar swamp-adapted plants in the marshes. There are few desert areas — even the mountains are rounded and smooth, and covered with grasses and shrubs. Seen from space, the land areas of the planet are almost entirely green. Bare rock is found only in the river valleys, where the streams have cut their way down to the lime and sandstone, and in ligneous outcroppings, where flint, quartz and quartzite frequently found. Obsidian is rare, of course, because of the lack of volcanic activity. There is clay to be found in some of the river valleys, with an appreciable alumina content, and rutile (titanium dioxide) is not uncommon. There are no concentrated deposits of iron ore, and hematite is almost unknown.

The land-living animal forms include orders similar to those found on Earth. There is a large variety of arthropods, including eight-legged insectlike forms of all sizes, up to a pseudo dragonfly with two pairs of wings and a wingspread which has been recorded at 86.5 cm. maximum. This variety lives exclusively on other insects, but there are several types dangerous to higher forms of animals. Several have dangerous bites (the poison is generally an alkaloid) and one insect can eject a stream of poisonous gas (reputed to be largely HCN) in quantity sufficient to immobilize a small animal. These insects are social in nature, like ants, living in colonies which are usually left severely alone by otherwise insectivorous organisms.

There are also many amphibians, small lizardlike forms with three fingers on each limb instead of the five that are common to terrestrial land vertebrates. They form an extremely important class, and there are some species that are as large as a St. Bernard dog at maturity. Except for some small and unimportant forms, however, the amphibians are confined to the marshy lowlands near the sea, and the rest of the land is dominated by a class resembling Earthly reptiles. Among these is the dominant species, a large, highly intelligent animal with a bipedal gait which balances itself with a rather stiff, heavy tail.

Two groups of the reptiles went back to the sea and engaged in successful competition with the fish. One adopted a completely streamlined form and is, outwardly, just another 30-foot fish. But its tail fin is in the horizontal plane and its internal structure shows its ancestry. It is the fastest thing in the waters of Lithia, doing nearly 80 knots when pressed (as it usually is by its insatiable appetite.) The other group of returned reptiles resembles crocodiles, and is competent either in the open sea or on the mud flats, although it is not very fast in either situation. Several genera of the reptiles have taken to the air, as did the terrestrial pteranodons. The largest of these has a wingspread of nearly three meters, but is very lightly built. It roosts mainly on the sea cliffs of the southern coast of the northeastern continent, and lives mainly on fish, and such of the gliding cephalopods as it can manage to catch above water. This flying reptile has a large assortment of sharp, backward-curving teeth in its long beak. One other species of flying reptile is of special interest, because it has developed something resembling feathers, in a many-colored crest down its long neck. They appear only on the mature reptile; the young are completely naked.

Some 100,000,000 years ago the land-living reptiles were almost completely wiped out by one of the smallest of their own family, which adopted the easiest method of making a living: eating the eggs of its larger relatives. The larger forms almost completely disappeared, and those that survived (such as the Lithian allosaur) are now almost as rare as the terrestrial elephant (as compared for instance, with the many elephant species of the Pleistocene.) The smaller forms survived better, but are not nearly so abundant now as they once were.

The dominant species is an exception. The female of this species has an abdominal pouch in which the eggs are carried until they hatch. This animal is about twelve feet tall at the crown, with a head shaped for bifocal vision. One of the three fingers on the free forelimb is an opposable thumb.