Today's frontier is outer space. Scientists accompany exploratory space flights in order to collect samples of what they find. These specimens are then returned to earth, studied, and identified in scientific laboratories.

The frontier of the past was the land. Following the discovery of America, naturalists came here with the same curiosity and courage as our pioneers of space have had in going to the moon.

The naturalists who came to Texas were looking for new forms of plant and animal life, for mineral deposits, and for fossils that might furnish clues to the nature of life thousands of years ago.

And early naturalist often suffered severe hardships in his search. He had to make his way through a wilderness where there were no bridges over rivers, where a road was little more than a footpath. Hostile Indians were an ever-present danger, and illness often developed from insect bites, scarcity of food, or harsh weather conditions.  Floods and storms carried away valuable tools and important collections. But perhaps the hardest part to bear was the loneliness. Illiterate settlers were highly suspicious of a stranger who spent his time digging up plants, catching insects, and packing frogs in alcohol.

What was it that caused these wilderness walkers to endure? Surely they did not expect great fame or money or immortality. It is more likely that these men were intrigued by "unknown," and that they liked nothing better than observing nature close at hand to find out its secrets.

The stories of these seven scientists have intrigued us, the authors, for more than four years. Their contributions to our knowledge of Texas increase in value when one walks those hundreds of miles with them through the wilderness.

From the Preface