It is true that all that remains of the once luxuriant vegetation are fragments preserved in stone, fragments which often show little of beauty or value to the untrained eye; but nevertheless these fragments can tell a story of great interest when once we have the clue to their meaning. The plants which lived when the world was young were not the same as those which live to-day, yet they filled much the same place in the economy of nature, and were as vitally important to the animals then depending on them as are the plants which are now indispensable to man. To-day the life of the modern plants interests many people, and even philosophers have examined the structure of their bodies and have pondered over the great unanswered questions of the cause and the course of their evolution. But all the plants which are now alive are the descendants of those which lived a few years ago, and those again came down through generation after generation from the plants which inhabited the world before the races of men existed. If, therefore, we wish to know and understand the vegetation living to-day we must look into the past histories of the families of plants, and there is no way to do this at once so simple and so direct (in theory) as to examine the remains of the plants which actually lived in that past. Yet when we come to do this practically we encounter many difficulties, which have discouraged all but enthusiasts from attempting the study hitherto, but which in reality need not dismay us. When Lindley and Hutton, in 1831, began to publish their classical book _The Fossil Flora of Great Britain_, they could give but isolated fragments of information concerning the fossils they described, and the results of their work threw but little light on the theoretical problems of morphology and classification of living plants. Since then great advance has been made, and now the sum of our knowledge of the subject, though far from complete, is so considerable and has such a far-reaching influence that it is becoming the chief inspiration of several branches of modern botany. Of the many workers who have contributed to this stock of knowledge the foremost, as he was the pioneer in the investigations on modern lines, is Williamson, who was a professor at Manchester University, and whose monographs and specimens are classics to-day. Still living is Dr. Scott, whose greatness is scarcely less, as well as an ever-increasing number of specialists in this country, who are continually making discoveries. Abroad, the chief Continental names are Renault, Bertrand, Count Solms Laubach, Brongniart, Zeiller; and in America is Dr. Wieland; while there are innumerable other workers in the field who have deepened and widened the channels of information. The literature on fossil plants is now vast; so great that to give merely the names of the publications would fill a very large volume.