Transactions. 37 
leads the salmon to return year after year to its native stream, 
and which has a striking parallel among birds, as in the case of 
the swallow, but pass on to other migratory fishes, first noticing 
the eels. Unlike the salmon, the eels spawn in the sea, if they 
do spawn at all. At anyrate, they went down to the sea to 
breed, and they came back again up the rivers ; and we find that 
the elvers, or young eels, come up about the month of May in 
large shoals. The older eels come up and run on spring tides, 
never waiting for a spate. 
The herring migrate, not to and from the Arctic regions, as 
was reported by all the older naturalists—worthy men in their 
time, and who have handed down to us a lot of erroneous infor- 
mation—but simply from deep to shallow water, and remain, I 
believe, very near our islands all the time. Their migration is 
very largely dependent upon temperature. To give an idea of 
the extraordinary numbers of the herring, if we allow one herring 
for every cubic foot, and assume a shoal to be a square mile in 
extent and eighteen feet deep, it would contain five hundred 
millions of the fish, And there were a great many shoals of 
vastly larger dimensions. Such were their immense quantity, 
and such their rapid rate of increase, that the’ whole quantity 
caught by man did not appreciably affect their numbers, and 
they would choke up the sea if they were not eaten by other fishes. 
One of the fishes most destructive to the herring was the cod, 
which followed the shoals, and has been found very frequently in 
the Solway now in the winter, at spots where the haddock used 
formerly to be plentiful, but from which it has disappeared. 
II. The System of Land Tenure in Scotland. 
By Mr J. W. Wuiretaw. 
In this paper the author remarked that the system of land 
tenure in Scotland was of feudal origin, but that very little 
_ feudalism now remained except in nomenclature, and the theory 
that the sovereign is the source and fountain of all rights in the 
land. He traced the history of Feudalism from the earliest 
times, showing how the various changes were introduced, and 
described the rites and ceremonies of investure. 
