ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixxix 



away, which towards the east assumes the character of a marshy plain, 

 and towards the west that of a much interrupted undulating table-land. 

 The waters of the Polish and German mountains flow into this low plain 

 from the south and from the east, first pressing themselves along its 

 southern barriers until they find an opportunity of breaking through 

 them, and reaching the intermediate lowlands, and then either fol- 

 lowing the general inclination to the north-west, or finding a shorter 

 outlet into the sea between the northern ridges." 



The second part gives a systematic view of all the geological forma^ 

 tions which occur in the district ; especially those existing along the 

 southern or northern boundaries, although occasionally a few insu- 

 lated outliers are met with, as the island of Heligoland, the rocks 

 of Liineburg, &c. No crystalline rocks have been found. The oldest 

 formation is that of the Trias, the Bunter Sandstein of which forms the 

 whole of the island of Heligoland, whilst at a distance of upwards of 

 a hundred miles to the south-east, the similar rocks of Liineburg 

 are found in the direct continuation of the line of strike. The rocky 

 reefs on the east side of the island of Heligoland show the regular 

 series of overlying formations, all dipping to the north-east or east- 

 north-east, consisting of Muschelkalk, Middle Jura, Hils-clay or 

 Gault, and above it the White chalk. The following formations are 

 then fully described by the author. 1. Trias formations. 2. Jurassic. 

 3. Chalk. 4. Tertiary. The insulated occurrence of some of these 

 formations at great distances from each other over this vast tract of 

 country is very remarkable. They point to the former existence of 

 islands, and of reefs in the tertiary seas, by which they were partially 

 worn dov^Ti and covered up. The occurrence of the Coral- rag or 

 Upper Jura on the banks of the Vistula, and at a great depth, discovered 

 in boring for salt, is pointed out as singular, being the only instance 

 of this particular member of the Jurassic formation having been 

 found in this part of the continent, inasmuch as the Jurassic rocks to 

 the eastward, in Courland, Lithuania, and Russia, are described by 

 Murchison, He Verneuil, and Keyserling as belonging to the Lower 

 and Middle Jura formations. 



The consideration of the Cretaceous formations follows next. The 

 author points out the important differences which existed between 

 the physical character of the two cretaceous seas, the one of which 

 occupied the Mediterranean basin and the South of France, the other 

 extending from England and the North of France between Germany 

 and Scandinavia into Russia ; but I do not understand on what 

 grounds the author assumes that this northern cretaceous sea (p. 54) 

 had no communication with the Western and Southern Ocean. 

 What barrier existed to the west or north-west to shut off its com- 

 munication with the Atlantic ? 



Of the Tertiary formations, the Brown-coal deposits are considered 

 by the author as the oldest, and he adopts Von Buch's opinion that 

 there is only one brown-coal formation in Europe. Yet he admits 

 that there are certain brown-coal formations, which, both from the 

 positions in which they are found and from their organic contents, 

 must have been caused by totally different agencies. He considers 



