"Immediately after breakfast we resumed our journey.
"In about half an hour M. Longuet complained of thirst; and I explained to him that in our circumstances all complaints were utterly futile: a statement which, for all its undeniable logic, seemed to afford him very little comfort. But fortunately at the end of another hour our ears were greeted by the agreeable sound of rippling water; and presently the ray of our electric lamp gleamed on a little stream which ran from some subterranean spring across the passage. M. Longuet flung himself down and began to drink. I hesitated, for it appeared to me, as a logician, that since we could not carry water along with us, to drink would only make us thirsty. Then I reflected that we should find other springs, and presently followed his example.
"We went on our way; and presently M. Longuet inquired of me whether there was no nourishment of any kind in the Catacombs on which we might sustain life when we had exhausted the resources of ham and the survivor of cannibalism. Fortunately I had visited the laboratory of the Catacombs of M. Milne-Edwards; and I could entertain him with an account of the fauna and flora of these caverns, on which he would be able, at need, to keep himself alive. I am bound to say that, contrary to my usual habit, I took great pleasure in this conversation about edible things. I felt indeed that such a subject was extremely old-fashioned; doubtless my pleasure in it arose from the exiguity of my breakfast.
"'My dear friend,' I said, 'it is always possible not to die of hunger, even if you never get out of the Catacombs. The flora, the cryptogamic vegetation, the mushrooms, in a word, of the Catacombs, will not suffice, I fear, to keep you alive. But fortunately wherever you find water in these caverns, you find food. You can always become an ichthyophagus."
"'What on earth is that?' he said suspiciously.
"'An ichthyophagus is a fish-eater.'
"'Ah!' he exclaimed with an immense satisfaction, 'there are fish in the waters of the Catacombs! I am very fond of fish!' He paused; then he added in a musing tone, 'After all, it is better to be an ichthyophagus than a cannibal.'
"'They are not large fish; but certain streams contain incalculable quantities of them.'
"'Really? Incalculable quantities?... Incalculable?... How large are they?' he said with great animation.
"'Oh, they are of different sizes. Generally they are small. But they are not at all disagreeable to eat. I was told about them when I went down to visit the Fountain of the Samaritan, a very pretty, good-sized spring in the Ossuary.'