MACKIE — ON THE BOTTOM- R0CK3. 
191 
know, the wide expanse of ocean waters was then untenanted by tho 
scaly tribe. 
And now I would say a few words why it is believed that these are 
the first traces of organized life upon our planet. 
While in Europe generally the older strata are much broken up and 
metamorphosed over isome large tracts, they are still in others but very 
little altered from their original condition of sediments ; and certainly 
not more so than the newer, though still vastly ancient, Silurian fossili- 
fei-ous deposits which succeeded them. For a thousand miles around 
New York, such ancient primitive strata stretch in a nearly level and 
unchanged condition ; and in Russia, vast plains and low hill-regions 
are similarly imaltered, until, in their range towards the igneous 
eruptive masses of the Urals, they become crystalline and meta- 
morphosed. 
In our own land, the old Cambrian rocks are not more altered in 
structural character than the Silurian beds above them, in which 
fossils are abundantly found. There is, therefore, po physical obstruc- 
tion to the preservation in the fossilized state of the living creatures 
and plants of the primeval lands or seas. 
We should bear in mind, however, that of these old rocks we have 
as yet but scanty knowledge ; that there are abroad, both in Europe 
and America, great masses of unfossiliferous rock underlying the 
Silurian strata which have never been searched for organic remains ; 
and that even in our typical region, the Longmynd, there are Cam- 
brian strata, both above and below the fossiliferous bands, in which as 
yet nothing has been found, and therefore we may etill hope to obtain 
further and more correct evidence of the fauna and flora of that vastly 
remote era. 
We have then, in mental vision, looked through the long vista of 
past ages, to seethe first-born lands of our mother-earth joyously bask- 
ing in the smiles of the sun, bathed in the tear-drops of the clouds, and 
scarred with the blasts of the waves and the storms. We have looked 
back, at least, to perceive a world governed by the same natural laws 
as our own. But how httle, after all, do we know of that primitive 
world ! How hard, through the mists and obscurities of myriad ages, 
to trace out any of its features ! As a babe unfolding its eyes to the 
