116 Dr Fleming’s Remai'hs on the Modern Sty'ata. 
and firmness which it may now be supposed to have acquired. 
It is also extremely probable, however, that the shaking or tre- 
mulous indications would make a deeper impression on the minds 
of the inmates of the lighthouse at first, than in later years. To 
a stranger such scenes as must be familiar to these people, 
perched upon a sunken rock in the middle of the ocean, with 
the waves often rising to the height of 60 and 70 feet upon their 
circumscribed dwelling, would be truly awful and terrific. 
Art. XVI. — Remarks on the Modern Strata. By the Rev. 
John Fleming, D. D. F. R. S. E. and M. W. S., Minister of 
Flisk. 
The history of the Earth, as determined by the documents 
of geognosy, gives indications of different epochs, each of which 
may be characterised by the peculiarities of the strata which 
were then deposited, and the organised beings with which the 
Earth was then peopled. The remains of the ancient animals 
and vegetables which are now found in these strata, have, in 
many cases, been preserved sufficiently entire to furnish the 
characters of the species, and enable an attentive observer to re- 
cognise the different individuals belonging to them, even when 
occupying different beds, and associated with other relics. In 
tracing, therefore, the history of any one species^ we find the re- 
mains of the individuals belonging to it, dispersed through a 
limited series of strata^ neither occurring in those of a more an- 
cient, nor in those of a more modern date. The associates of this 
species, or the other species, the remains of which occur in the li- 
mited series of strata, are in like manner circumscribed in their 
geognostical distribution. If we now attend to the position oc- 
cupied by the strata of this series, in reference to those of other 
or newer series, — their mechanical structure and chemical con- 
stitution ; and, if we determine the species of organised beings, 
the relics of which are imbedded in the strata of this series, we 
may consider the history of the series or group as complete. 
The characters of several of such series have, to a considerable 
extent, been determined, thereby establishing so many important 
epochs in the Earth’s history. 
It seems to be determined that the organised species, if con- 
