“However, suppose you try our diet while I explain.”

The four once more looked at each other.  The doctor was the first to take a sip of one of the cups handed to him, and Van Emmon was the last; the geologist waited to see the effects upon the others before gingerly tasting of the thickest, darkest liquid of them all.  Another taste, and he discovered that it was very good, and that he was exceedingly hungry.

“Very delicately flavored,” commented Billie, after emptying her fourth glass, a golden fluid with a slightly oily appearance.

“Delicately is right,” said the doctor.  “This stuff is barely flavored at all, Estra.”

The Venusian was also “eating.”  “We much prefer them all that way,” said he.  “I suppose you would consider our tastes very finicky, on Earth; but the fact is we are able to distinguish between minute variations in flavoring such as would escape all on earth except a humming-bird.”

“I suppose,” remarked the doctor, smacking his lips over a reddish solution with a winelike flavor, “I suppose we can expect something of that sort on the Earth, too, in time.  Originally mankind was only able to distinguish fresh from stale, and animal from vegetable flavors.”

After a while Myrin went on:  “You know, the processes of nutrition, as they take place among your people, are extremely wasteful.  You have probably heard it said that ’the average human is only fifty per cent efficient.’  That simply means that digestion, assimilation and excretion require half the energy which they secure from the food.

“Now, the articles you have just swallowed require very little work on the part of your digestive apparatus, and none at all upon your eliminating tract.  The food is almost instantly transformed into fresh blood; if I am not mistaken, you already feel much refreshed.”

This was decidedly true.  All four felt actually stimulated; Van Emmon instantly suspected the food of being alcoholic.  As he continued to watch its effect, however, he saw that there was no harmful reaction as in the case of the notorious drug.

“I think I can now tell you how we produce enough food for the three and a half trillion of us, despite our lack of farms and orchards,” said Myrin rising.

Returning to the air-craft, the four were taken a short distance in a new direction, and again descended, this time transferring to an elevator which dropped far below the surface.  They came to a stop about ten floors down.

“Naturally,” said Myrin, “we reserve all the surface for residence purposes; although, it is possible to live down here in comparative comfort, since we have plenty of electrical energy to spare.”  And she operated a switch, flooding the place with a brilliant glow.  Thrown from concealed sources, this light was quite as strong as the subdued daylight which they had just left.  “But unless we were free to fly about as much as we do, we should feel that life was a bore.  Nobody stays below any longer than is necessary.