EHRENBERG ON INFUSORIA IN IGNEOUS ROCKS. 77 



times, but there was no trace of a spring on tlie bare barren summit, 

 nor could any channel be discovered on the declivity down M'hich 

 such spring might have poured. But the amphitheatre which the 

 form of this isolated hill presented was extremely striking. Many 

 delicate well-preserved organic remains of animals and plants*, 

 some of them known, but some belonging to species now extinct, 

 distinctly prove that this polishing slate belongs to an ancient di- 

 vision of the tertiary period, immediately subsequent to the chalk, 

 and at the same time that it was a quiet deposit in fresh water, ex- 

 hibiting by its organic remains a gradual passage from the animal 

 to the vegetable kingdom. The thin superficial coating of gravel 

 seems to show that the whole has been since subjected to the action 

 of currents of water. 



The environs and the springs of Toplitz and Carlsbad were also 

 objects of investigation during the author's brief stay, and he looks 

 forward to a time when he may be able to follow out these investi- 

 gations in greater detail ; but he was particularly struck with the 

 large crater-shaped valley of Franzensbad, whose diameter is about 

 four miles, and within which is the little volcanic cone of the Kam- 

 merbiihl. In this spot were exhibited many highly interesting con- 

 ditions and relations of the most minute forms of organic existence. 



It was evident from the first glance that the infusorial siliceous 

 earth played a very important part in the valley of Franzensbad. 

 That it was indeed by no means a mere local pheenomenon exhibited 

 in the little hillocks or heaps on the surface, as had been originally 

 supposed, but existed as a regular and extensive deposit beneath 

 the coating of vegetable soil, had been noticed before by Dr. Palli- 

 ardi, but the author observed its extension in so many places besides 

 those noticed by Dr. Palliardi, wherever the denuded surface Avas 

 visible, and it appeared to be so completely an integral part of the 

 turf or bog earth, that the whole valley seemed completely covered 

 with it, and in fact the whole of the turf, whether its thickness is 

 one or twenty feet, belongs more or less exclusively to this forma- 

 tion. 



Near Franzensbad the development of Pi7inularia viridis in great 

 masses of siliceous earth is extremely striking, and at the east end of 

 the valley the presence of Campylodiscus clypeus is equally abun- 

 dant in the same manner. Similar formations were observed by 

 the author to be still in progress, but the great mass of the deposit 

 consists of the mere empty infusorial cases. Scarcely less extensive 

 than these are the deposits of massive carbonate of iron in the neigli- 

 bourhood of the acidulous springs, which commonly, but not al- 

 ways, contain fragments of Gaillondla fcrruginca. In the midst of 

 the true siliceous infusorial earth there also occurs phosphate of iron 

 in the form of blue vivianite, above which the fen -mud- appears, and 

 is often quite filled with and hardened by the black iron pyrites. 



Here however it will be seen that neitiier the mineralogical nor 

 the physiological conditions are wanting for the combination of the 

 materials, and the black pyrites is manifestly a local and subsequent 



* There is an extremely rich and beanliful collection of these in the nuiseum 

 in the Lobkowitzian palace, but the specimens have not yet been described. 



