1866.] GUMB'EL — ON LAURENTIAN ROCKS. 97 



minerals, although presenting certain dense portions which seemed 

 to indicate the presence of some foreign matter. These portions 

 however showed only a cellular structure, like that in the specimen 

 from Hohenberg, without any tubuli ; nor did etching succeed in 

 developing any structure in these wholly calcareous specimens. 

 When therefore carbonate of lime both constitutes the skeleton, 

 and replaces the sarcode, there is evidently little hope of recognizing 

 these organic forms. If however the flaky pellicles which remain 

 suspended in the acid after the solution of the lime, in these 

 almost wholly calcareous specimens, are examined, they present a 

 very great resemblance to the similar pellicles from the Eozoon 

 limestone of Steinhao-, already figured, which have such a striking 

 resemblance to organic forms. The careful examination of the 

 limestone from many other parts in the Fichtelgebirge, affords 

 evidence of organic life similar to those of Hohenberg ; thus 

 tending more and more to fill up the interval between the 

 Lauren tian gneiss, and the primordial zone of the Lower Silurian 

 fauna. We may therefore reasonably hope that in the study of 

 these more ancient rock-systems, which geologists have only 

 recently ventured to distinguish, paleontological evidence will be 

 found no less available than in the more recent sedimentary 

 formations. The inferences which we are permitted to draw from 

 the discovery of organic remains in these ancient rocks, confirm 

 the conclusion to which I had previously arrived from the study 

 of the stratigraphical relations, and the general character of these 

 ancient rock-systems ; viz., that there exists, in these ancient 

 crystalline stratified rocks, a regular order of progress determined 

 by the same laws which have already been established for the 

 formations hitherto known as fossiliferous. 



I cannot conclude this notice of the preliminary results obtained 

 in the investigation of the ancient Eozoon limestones of Bavaria, 

 without adding a few observations upon some foreign crystalline 

 limestones. It is well known that the crystalline minerals, which 

 in numerous localities are found in these limestones, often present 

 rounded surfaces, as if they had at one time been in a liquid state. 

 As examples of these, Naumann mentions apatite, chondrotite, 

 hornblende, pyroxene, and garnet. The edges and angles of these 

 are often rounded ; the planes curved or peculiarly wrinkled, 

 and only rarely presenting crystalline faces ; having in short a 

 half-fused aspect, and offering a condition of things hitherto 

 unexplained. One of the best known instances of this is found in 



Yol III. G No. 2. 



