“Matanzas is, as a commercial city, next in importance to Havana,” said the professor as they rode along. “It has a large shipping and the population is nearly forty thousand. Not far from the city are located the Caves of Bellamar. I never visited them, but they are said to be of uncommon interest and beauty.” “Let us go by all means!” cried Darry. “I just love caves and volcanoes and high mountains.” Matanzas was reached in the middle of the forenoon, and before dining they paid a visit to the fortifications which had taken active part in the war, and also to a number of public buildings. Then they dined, and after that set out for the caves on muleback, along with a native guide, who owned the mules and who said he could take them around to every point of interest. The mule he rode interested Darry very much, for, as old readers know, he took naturally to any animal that could be saddled. The mule was not very large, but he looked powerful and his gait proved a surprise. “I really believe he could win a race on a pinch!” said Darry. “Do you?” queried Hockley. “I’ll go you for a mile.” Darry was surprised to receive such a challenge from the lank youth, but he did not hesitate to accept, and away went both lads before either the professor or the guide could stop them. At first it was nip-and-tuck, for Hockley’s beast was also swift of foot, and it was not long before the racers passed out of sight beyond a turn. Professor Strong began to look serious but the Cuban guide only smiled. “They will not run far,” he said, in Spanish. “And when they drop into a walk they will pay up for their speed by going slower than ever.” Nevertheless, the others set off after the two in advance, for the guide feared they would take to the wrong road, one leading into the country and away from the caves. This was just what Darry and Hockley did, and soon they came to what was little better than a rough trail, with thatched huts on either side. The mules kept together at first but presently Darry forged ahead. “Whoop I here we go!” he yelled. “Look out for the mountain express!” And then he had to cling fast, as the mule switched his heavy-ended tail and kicked up with his rear hoofs. Soon Darry reached what seemed to be the middle of a settlement, with huts on all sides. Here was a big stone cistern, filled with water, and with the top wide open. Several natives were at hand, some of them with buckets and shells. As soon as he reached the cistern the mule Darry rode came to an abrupt halt. Looking back the boy saw that Hockley was now having his hands full with his steed, which was rearing and plunging in a most surprising fashion. “Look out, Glummy, or he’ll throw you!” he sang out. “He’s getting his dander up!” “He shan’t throw me!” panted Hockley. “I’ll show him who is master!” And he hit the mule on the neck with his fist.