THE WATER TRAIL FROM GEORGETOWN TO AREMU. We allowed ourselves only forty-eight hours in Georgetown to unpack our specimens and prepare for our second expedition into the “bush.” This time we were to leave the coast and strike straight inland, passing up the Essequibo River to Bartica, thence via the Mazaruni and Cuyuni to the Aremu and the Little Aremu rivers. Near the head-waters of this last stream was the gold mine which marked our journey’s end, deep within the wilderness. On the morning of March 23d, we left Georgetown on one of Sproston’s steamers en route for Bartica. A pair of Gray-breasted Martins[122] accompanied us, and we found that they were nesting in an angle between two beams of the main deck covering. Young birds were in the nest, so the Martins must have accompanied the steamer on many of the alternate day trips between Georgetown and Bartica. Not only this but the river boat exchanges routes every two weeks with her sister steamer which is plying on the outside northwest route to Morawhanna, the fortnightly change from fresh to salt water doing away with all need for keel cleaning. So these birds had started their nest while the boat was making her sea trips. During much of the time we were on the boats the birds kept flying out to each side over the water in pursuit of insects for their brood. They sometimes went far ahead or out of sight a half mile to shore. After entering the wide estuary mouth of the Essequibo we passed Leguan and Hog islands, each over ten miles in length, while above these a succession of smaller islands appeared. The river is about three miles in width, fringed with mangroves, and we saw no life on shore save occasional Cocoi Herons[31] feeding on the flats. [Illustration: FIG. 101. GRAY-BREASTED MARTINS NESTING ON THE STEAMER.] The Essequibo is the largest river in the colony and rises in the extreme south, somewhere in the Acarai Mountains near the equator, some six hundred miles inland. Like all the great rivers of this region it is navigable by steamers for only a short distance, rapids and cataracts barring the way about fifty miles above the mouth. The first great tributary is the Mazaruni, entering from the southwest and touching with its uttermost head-waters the very base of that mysterious lofty plateau, Roraima, on the borders of Brazil. We landed at the very apex of the point of land between the Essequibo and Mazaruni rivers,—the village of Bartica or Bartica Grove. It is a most dilapidated place, half in ruins, a single street of miserable houses filled with blacks and coolies.