
- Parr I Secr. iii] FJORDS AND SUBSIDENCE. 283 
organisms, although, as Mr. Wallace has shown in the case of the 
~ supposed “Lemuria,” some of the inferences have been unfounded 
and unnecessary.!. The present distribution of plants and animals 
is only intelligible in the light of former geological changes. Asa 
single illustration of the kind of reasoning from present zoological 
groupings to former geological subsidence, reference may be made to 
the fact, that while the fishes and molluscs living in the seas on the 
two sides of the Isthmus of Panama are on the whole very distinct, 
- a few shells and a larger number of fishes are identical ; whence the 
inference has been drawn that though a broad water-channel originally 
separated North and South America in Miocene times, a series of 
elevations and subsidences has since occurred, the most recent sub- 
-mersion having lasted but a short time, allowing the passage of 
_ locomotive fishes, yet not admitting of much change in the com- 
_ paratively stationary molluscs.? 
_ Fjords.—An interesting proof of an extensive depression of the 
north-west of Hurope is furnished by the fjords or sea-lochs by which 
that region is indented. A fjord is a long, narrow, and often 
singularly deep inlet of the sea, which terminates inland at the 
mouth of a glen or valley. The word is Norwegian, and in Norway 
_ fjords are characteristically developed. The English word “firth,” 
however, is the same, and the western coasts of the British Isles 
furnish many excellent examples of fjords, such as the Scottish Loch 
Hourn, Loch Nevis, Loch Fyne, Gareloch; and the Irish Lough 
Foyle, Lough Swilly, Bantry Bay, Dunmanus Bay. Similar in- 
dentations abound on the west coast of British North America. Some 
of the Alpine lakes (Lucerne, Garda, Maggiore and others), as well 
as many in Britain, are inland examples of fjords. 
There can be little doubt that, though now filled with salt water, 
fjords have been originally land valleys. The long inlet was first ex- 
~cayated as a valley or glen. The adjacent valley exactly corresponds 
in form and character with the hollow of the fjord, and must be 
regarded as merely its inland prolongation. That the glens have 
been excavated by subaerial agents is a conclusion borne out by 
a great weight of evidence, which will be detailed in later parts of 
this volume. If, therefore, we admit the subaerial origin of the 
glen, we must also grant a similar origin to its seaward prolongation. 
Every fjord will thus mark the site of a submerged valley. This 
inference is confirmed by the fact that fjords do not, as a rule, occur 
singly, but, like glens on land, lie in groups; so that when found 
intersecting a long line of coast such as that of the west of Norway, or 
the west of Scotland, they serve to show that the land has there sunk 
down so as to permit the sea to run far up and fill submerged glens. 
_ Human constructions and historical records.—Should 
the sea be observed to rise to the level of roads and buildings which 
1 “Tgland Life,” 1880, p. 394. In this work the question of distribution in its 
geological relations is treated with admirable lucidity and fulness. 
2 Wallace, “ Geographical Distribution of Animals,’ i. pp. 40, 76. 
