492 
THE LIIMFJORD. 
striking phenomenon was the sudden destruction of almost all 
the fresh-water fish previously inhabiting this lagoon, which 
was famous for its abundant fisheries. Millions of fresh-water 
fish were thrown on shore, partly dead and partly dying, and 
were carted off by the people. A few only survived, and still 
frequent the shores at the mouth of the brooks. The eel, 
however, has gradually accommodated itself to the change of 
circumstances, and is found in all parts of the fjord, while to 
all other fresh-water fish, the salt water of the ocean seems to 
have been fatal. It is more than probable that the sand washed 
in by the irruption covers, in many places, a layer of dead fish, 
and has thus prepared the way for a petrified stratum similar 
to those observed in so many older formations. 
“ As it seems to be a law of nature that animals whose life 
is suddenly extinguished while yet in full vigor, are the most 
likely to be preserved by petrification, we find here one of the 
conditions favorable to the formation of such a petrified stratum. 
The bottom of the Liimfjord was covered with a vigorous 
growth of aquatic plants, belonging both to fresh and to salt 
water, especially Zostera marina. This vegetation totally 
disappeared after the irruption, and, in some instances, was 
buried by the sand; and here again we have a familiar phe¬ 
nomenon often observed in ancient strata—the indication of 
a given formation by a particular vegetable species—and when 
the strata deposited at the time of the breach shall be accessi¬ 
ble by upheaval, the period of eruption will be marked by a 
stratum of Zostera , and probably by impressions of fresh¬ 
water fishes. 
u It is very remarkable that the Zostera marina, a sea plant, 
was destroyed even where no sand was deposited. This was 
probably in consequence of the sudden change from brackish to 
salt water. * * It is well established that the Liimfjord 
communicated with the German Ocean at some former period. 
To that era belong the deep beds of oyster shells and Ca/rdium 
edule , which are still found at the bottom of the fjord. And 
now, after an interval of centuries, during which the lagoon 
contained no salt-water shell fish, it again produces great num- 
