besides by water that most of the streams flowing down the sides of the hills take by preference subterranean courses. These beds are likewise unstratified, but seem to be roughly divisible into three layers, the upper and lower containing a considerable quantity of calcareous matter distributed through the mass, so as to effervesce violently with acids, while in the middle the lime and other soluble salts have, for the most part, segregated into long irregular nodules, curiously twisted and contorted, and most of them having their longer axis vertical. By means of this intermediate layer the beds may be noticed to dip at extremely small angles, and generally towards the south of east. Like the former, this series has suffered considerable denudation ; but patches of it may be seen here and there upon the sides of the adjacent hills to a height of about 500 feet. In Shantung a similar clay seems to form the surface of the higher plains, specimens in my possession from that locality being precisely similar in appearance and structure. With this exception, I do not know of its occurrence elsewhere in China. I have met with no fossils of any sort in these clays, nor do I know of any which can with any reasonable probability be referred to them. Similar clays in India have, I believe, been referred to a Pleistocene date.
Of still later date, and at the present day proceeding in their formation, are the alluvial deposits of the great rivers, more especially the Hwangho and Yangtse. Within historical times the growth of their united delta has been so rapid, and the changes of the coast-line and the river- channels so numerous, that the ancient history of these regions seems almost incomprehensible till studied by the light of modern research. With the continual advance of the coast-line the level of the rivers in the interior seems to have been continually raised ; and from this cause, in many localities in the interior of the country, alluvial deposits of modern date cover up the older clays. In the plains of Hupeh and Anhwei the Yangtse overflows annually, forming large lakes, sometimes fifteen or twenty miles in breadth. In Kiangsi, in the basin of the Poyang lake, and in Hunan in that of the Tungting, similar floods occur. But it is along the course of the Yellow River that the effects of the gradual elongation of the channel are most apparent ; and in these districts, from the earliest dawn of history, we find the care of the embankments uppermost in the minds of Chinese statesmen. Tradition hands down the half- heroic Yu, the model of Chinese emperors, less as a politician or a successful general than as an engineer. The semifabulous Yu-kung, apparently a record more of his political arrangements than of his engineering labours, has, by the glosses of later commentators, been made to represent his struggles with and final victory over the two great rivers. The entire subject, however, is too wide and of too great importance to be taken up at the tail-end of a paper such as this. Count D'Escayrac de Lauture, in the ' Proceedings of the Societe de Geographic' for 1862, and more recently Mr. Pumpelly, as I learn in 'Silliman's Journal,' have treated more or less fully of the changes of the Yellow River ; while the Rev. J. Edkins, in the second volume of the 'Transactions of the North China Branch
