They rolled merrily over the track and in a little while had passed Gatun Station, and the point they visited in their excursion to inspect the work on the canal. They wound among the low hills and along the bank of the Chagres River, catching pretty views here and there, and passing several unimportant stations without stopping. One of the officials pointed out the cottage which was the favorite residence of Mr. John L. Stephens during his connection with the railway, and also a gigantic tree which has long been known as "Stephens's tree." Other objects of interest were indicated, and there was not an idle moment in the whole journey. [Illustration: BRIDGE ACROSS THE CHAGRES RIVER AT BARBACOAS.] The railway crosses the Chagres River at Barbacoas, where there is a fine bridge, which has withstood the shocks of that capricious stream in a manner that reflects creditably upon its builders. A little beyond Barbacoas they met a train bound eastward, and waited a short time on a siding to enable the locomotive and its burden to get out of the way. The delay gave an opportunity for a brief excursion into the tropical forest, which came close up to the railway, as it does for the greater part of the distance between Aspinwall and Panama. [Illustration: MEETING A TRAIN.] Frank and Fred were accompanied by one of their new friends, who seemed to be well versed in the botany of the country. The first tree to meet their gaze was a palm, and while they were noting its peculiarities their guide told them there was no place in the world where so many varieties of the palm could be found together as on the Isthmus. "There are," said he, "twenty-one different species of palm-trees; I am informed that three or four more have been found in the vicinity, but I have not seen them. From one of the well-known varieties is extracted the palm-oil of commerce; another produces a sweet sap from which the natives distil a wine they use freely as a beverage; there is the 'sugar palm,' from which sugar is made; the 'sago palm,' which produces sago, but of a quality inferior to that of the Malay Archipelago; the 'ivory palm,' which supplies vegetable ivory; the 'cabbage palm,' whose stalks resemble the cabbage in appearance and taste; and the 'glove palm,' from which bags for holding grain or kindred things are readily obtained. Houses, weapons, domestic utensils, and many other things are made from the leaves, stalks, fruit, bark, or wood of the palm, and the tree is quite as necessary to the existence of the natives of the Isthmus as is the bamboo to the inhabitants of tropical Asia." [Illustration: THE SINGING HUMMER.]