Monella passed his hand across his brow in the half-dreamy manner that was his at times, as though striving to collect his thoughts, or to arrest and force into shape some half-formed conception that had flitted across his mind and escaped his grasp. For a minute he stared vacantly away into the distance and was silent. Then, with a look as though of pain at failing to catch the fleeting image, he turned away, saying simply, "I cannot tell you." During the days that followed, Templemore passed much of his time in the museums; time that Elwood spent in a lover's dream of happiness with Ulama. In the relics of the former history of this strange people, Templemore took a deep interest; and in the archives and ancient manuscripts he found many evidences of the former existence of scientific and engineering knowledge that astonished and perplexed him. On the true meaning and import of some of these he sought the help of Monella, who would frequently accompany him in these visits, and, from his better knowledge of the language, was able to assist him to unravel their curious contents. "These people must once have been great engineers and architects!" he exclaimed in surprised admiration on one of these occasions. Monella smiled and made reply, "There is nothing so surprising in that, if you comprehend the true significance of the gigantic earthworks still extant in many places on this continent. Have you seen any of them?" "No; but I have both heard and read of them." "I have seen them; and I tell you your mind can form no idea of their extent, of the scientific knowledge and the prodigious amount of time and labour that must have been expended on them, unless you actually see them. They are of various forms, mostly geometrical figures upon a vast scale--miles in extent. The wonderful thing is that a certain figure is repeated exactly in different places hundreds of miles apart. Yet you shall take your cleverest engineers of the present day, give them the advantages--or supposed advantages--of all your modern discoveries and machinery, and scientific instruments, and, say, unlimited workpeople to do their building, and _then_ it would tax all their skill to construct a work _exactly_ similar to one of those great figures. Yet now, upon some of them, trees are growing that must be over a thousand years old!" "And what were they for--what was their object?" Templemore asked. Then there came over the other's face again that curious look as of one seeking for a lost recollection; but it seemed to evade him, and he answered somewhat as before, "I think I ought to be able to tell you," he replied, "but I cannot now seem to remember." It was while thus together one day that Templemore asked him for some further information concerning the 'Plant of Life.'