History of the Peloponnesian War

Divers also swam in under water on the side of the harbour, dragging by a cord in skins poppy-seed mixed with honey, and bruised linseed; but though these escaped unobserved at first, precautions were afterwards taken against them.

Indeed each party contrived in every possible manner, the one to throw in provisions, the other to prevent its being done without their observation.

When they heard at Athens the circumstances of the army, that it was thus being harassed, and that corn was thus taken in for the men in the island, they were perplexed, and afraid that winter might surprise them in the blockade. For they saw that both carrying provisions round the Peloponnese would then be impossible—at the same time they were in an uninhabited country, [where they could get none themselves,] and even in summer they were not able to send round sufficient supplies for them—and that the blockade by sea of so harbourless a country could not be continued; but that the men would either escape through their giving up their guard, or would watch for a storm, and sail out in the boats that carried the corn in for them.

Above all, they were alarmed by the conduct of the Lacedaemonians; for they imagined that it was from their having some strong point on their side that they made no more overtures to them;

and they regretted not having assented to the treaty. Cleon observing their suspicions of him, with regard to the obstacles thrown in the way of the convention, said that their informants did not speak the truth. When those who had come with the tidings advised them, if they did not believe them, to send some commissioners to see, he himself, with Theogenes, was chosen by the Athenians for that purpose.