118 
ALLIS SHAD. 
Of the Trichaios, ^yhich is our Shad, Aristotle says, B. 8, C. 
13, that it enters the Eiver Ister, or the Danube, and then, 
•where this river divides into branches, it passes down into the 
Adriatic Sea; and in proof of this his argument is, that it is 
seen to enter the river, and is not known to come out of it 
again; whereas in the Adriatic they are not known to enter, 
but are caught as they come out. Aristotle could not have 
been acquainted with the geography of the higher portion of 
the Danube, and he may have given credit to the error 
contained in the received accounts of the proceedings of the 
Argonautic expedition; where instead of what really happened, 
which evidently was, that in order to escape pursuit the ship 
was conveyed across the Isthmus of Perecop, from the west side 
of which the adventurers sailed along by the mouth of the 
Danube into Greece, it was believed that they had gone up 
that river, and by some other branch had passed down to the 
Adriatic; a supposition which in somewhat later times gave rise 
to the further absurdity of believing that Ulysses had gone from 
Troy to the distant region of Italy, in his endeavour to reach 
his home in a Greek Island. It is plain that this wanderer 
had gone into the Black Sea in his endeavour to escape the 
danger threatened to his fellow warriors; and it is there the 
dangerous islands, from which the Argonauts had so narrow an 
escape, were his Scylla and Charybdis, and another island was 
the home of his Circe, where Medea had leamt her skill in 
sorcery. But the Eoman Pliny, in a later age, had become 
acquainted with the geography of these regions; and therefore 
while he copies the Natural History of the learned Greek, he 
is compelled to add, that the passage of this fish from the 
Danube to the Adriatic was by subterranean channels; for he 
was awai e that it accomplished at all it must be by a way not 
known to observation. Indeed, it does not appear probable 
that the Shad is at all accustomed to ascend to the higher part 
of this river; since Dr. Eeisingcr, in his account of the fishes 
of Hungary, does not mention this species as coming within 
his knowledge. They avoid turbulent streams or rapid currents, 
unless for a short way; but whether foul or clear is of small 
consequence. 
It was also known to the Egyptians by ascending the Nile 
from the sea, and it is common along the coasts of Europe up 
