Ardea pseudocypraea

When they were close to the precipitous banks of the Sarine, the Professor halted and leaned on his alpenstock while the party gathered beside him. “And now,” he announced, “I invite you to join me in scrutinizing the long-necked birds that do not perch on, but adhere to, the steep rock-faces of this gorge. See how they slither up and down the vast surfaces without fear of falling, yet without the need, nor the gift, of flight. Though their markings vary, they all belong to one species: the Cowry egret (Ardea pseudocypraea), which travels where it pleases by means of its ventral ‘foot,’ which operates like that of a snail, but in much larger dimensions than any gastropod.”

“It it a close relation of the Moaning slug-bird?” inquired Dick.

“No, as that is a gastropod with bird-like attributes, while this is just the opposite. You will observe that it appears to lack claws or legs at all — but look closer: where one expects spindly, prehensile limbs are a pair of sinewy stumps that provide essential aid in the bird’s locomotion. There is even a featherless, ridged area, with horny tissue like that found on a talon: this is the vestigial, proper foot, which grinds against rock and gravel without bringing harm to the leg or the animal.”

“Could it be said to possess five limbs, then, instead of the usual four?” asked Beatrice.

“No. For that fifth part, which we casually refer to as a ‘foot,’ is a muscular organ, extending from the stomach, which is ambulatory in function but not classified as a limb when possessed by avians. It will hold our interest however we label it, for the slime it secretes is unlike any snail’s, and an industry unto itself.

“The basic duty of a Cowry egret farmer — of which there are countless in this area — is to keep a well-fed male of the species positioned over a circular band which forms the topmost ring of a tiered structure that to us resembles a certain kind of cake-stand, or perhaps a bottle-rack, but is actually a unique and highly specialized device. For each tier holds a different sieve or filter, designed to strain the mucus in stages, so that the pan at the base collects a purified substance, suitable to be combined with pulverized grapefruit seeds and quicklime, then baked…”

“To make rohumbabisque!” exclaimed Dick, delighted at his quick deduction.

“Exactly. And it is only here, in this canton of the Swiss Confederation, that rohumbabisque is produced.”

“Because only here the Cowry egret flourishes,” said Beatrice, reflecting. “The people must be prosperous; I hope they are thankful. I never wondered where rohumbabisque came from.”

“Many never do. Like ambergris, or glue, or khneblunk — or even candle-wax, rohumbabisque is a substance we take for granted, though it is in fact a joint product of Nature and Man’s ingenuity. It is easy to ignore these things, yet we are wiser when we consider how our lives are enriched.”

“And to think,” said Dick, “without rohumbabisque, I should not be able to enjoy a single round of 'blonts and priggoads'. How dull life would be were it not for this humble Swiss bird.”

From: T. Altidrean Jingross, A Zoological Jaunt through Central Europe. New York: Whispitt & Co., 1891: p. 188.