On 8 May 1733, when the master builder Johan Gråberg went to inspect the quarry of Wamlingebo (now Vamlingbo) in Sweden, two of the quarrymen came running up from the excavation in a most excited state. While cutting large blocks of sandstone more than 10ft (3m) below the surface, one of them had discovered a large frog sitting in the middle of a sizeable boulder he had just cut in two with his hammer and wedge. Gråberg followed the workmen down into the quarry, where he too was startled by the sight of the frog sitting inside the boulder. Part of the stone nearest the frog was so porous that the violence of the blow had fragmented it, destroying the impression of the animal’s body. Since the frog was in a lethargic state, Gråberg could not provoke it to move, even when he lifted it out on a spade. When he touched its head with a stick, it closed its eyes. Its mouth was covered with a yellow membrane. The master builder’s examination of this mysterious stone-frog was cut short by his impatience: for some reason, the Swede wantonly beat it to death with his heavy shovel. The quarrymen put the flattened body of the supernatural animal on a polished slab of stone and laid it in state in their cabin.

	In a cavity near the middle, a large Toad was found as Bigg as a man's fist...

Later the same afternoon, Gråberg was struck by belated qualms of conscience “for being the Slayer of that extraordinary Animal, which might have lived for many hundreds of years within its stony Prison”. He returned to the quarry and took the frog with him to Stockholm, where he showed it to several scholars. Among them was a provincial medical practitioner named Dr Johan Pihl, who submitted a paper on the strange stone-frog to the Swedish Academy of Sciences. But only the brief section containing Gråberg’s account of the discovery of the frog was published in the Academy’s Transactions. It was illustrated with an engraving of the frog’s cadaver, showing a section of the quarry where it was found.

A Chorus of Frogs

Mr Gråberg’s paper on the stone-frog was translated into German, Dutch, French and Latin. It aroused much interest in entombed toads and frogs among European scholars. In the old chronicles of monsters and marvels, these investigators found several ancient tales resembling that of the Swedish master builder. In William of Newburgh’s Historia Rerum Anglicarum, it was related that in 1186 a large stone was found that appeared, in fact, to be made up of two stones joined by some adhesive matter. When a bishop ordered it to be split, a living toad with a gold chain around its neck was sitting in its centre. Everyone understood that this could be nothing but sorcery, and the stone was buried intact without any of the witnesses being brave enough to divest the toad of its ornament. A more reliable observation was reported by the old chronicler Fulgosius: in his treatise de Mirabilibus, published in 1509, he briefly reported that at Autun several people had seen a fat toad being found inside a stone.

In 1575, the famous surgeon Ambroise Paré had ordered some workmen at his vineyard near Meudon to break up a couple of large stones. In the middle of one of them was found a large living toad. Paré was greatly astounded, since the stone had no visible opening to the outside. He wondered how the animal had been born and how it had been able to grow and stay alive inside the stone, but the quarryman said that this was not the first time he had discovered toads, and indeed other animals, in the centre of stones. Paré concluded that the entombed toads must have been formed through spontaneous generation: some humid matter within the stone had putrefied to produce the animals.

Another extraordinary phenomenon was reported by Dr PJ Sachs in his Gammarologia Curiosa. In 1664, a friend of his, Count Hermann of Gleischen and Hatzfeld, had visited the castle of Count Fürstenberg near Cologne. The latter nobleman had in his possession a round stone, which contained a living frog. When the stone was lifted up, the frog croaked loudly; this strange, hollow sound was likened to “Koak brekekex!” – the chorus of frogs in Aristophanes’s play The Frogs. When the stone was finally broken, the frog jumped out alive.

In his Natural History of Staffordshire (1686), Professor Robert Plot, the first Keeper of the Ashmolean Museum in Oxford, described no less than three cases of a ‘toad-in-the-hole’, as the phenomenon has become known in the British Isles (after the traditional dish of sausages embedded in Yorkshire pudding or batter, which dates from at least the 18th century). One of these concerned a large limestone that had been placed as a stepping-stone for passengers in the middle of a cartway over two rills. People had been puzzled by a loud croaking sound coming from this stone, and at length it was decided to break it open. As Plot reported: “In a cavity near the middle a large Toad was found as Bigg as a man’s fist, which hop’t about as briskly, as if it had been bread in a larger room.” An even more astounding case came from Statfold, where the top-stone of the spire of the church tower had fallen down and broken. “There appear’d a Living Toad in the Center of it, which (as most of the rest are said to doe) dyed quickly after it was exposed to the Air.”

A Series of Experiments

In September 1770, a live toad was found inside a stone wall at the castle of Le Raincy, France, stirring further interest in the entombed toad mystery. M. Jean Guéttard, a Fellow of the French Academy of Sciences, described the toad-in-the-hole as one of the most puzzling enigmas in natural history, and urged his fellow academicians to spare no labour in solving this mystery, which had baffled naturalists for more than 200 years. His colleague M. Louis Hérissant performed an ambitious series of experiments to test the capacity of toads to withstand hunger, thirst and suffocation. Three toads were put in boxes, which were sealed with plaster in the presence of several academicians. When they were opened 18 months later, two of the toads were found to be alive. The boxes were sealed and put away a second time, but Hérissant was not destined to see the result of his experiment: he died in October 1773. In his eulogy on Hérissant, Guéttard mentioned that this gentleman, apparently a scientist to the last, had left him the boxes of toads in his will, with instructions to open them some time after his death. When this was done, the toads were all dead and desiccated.

Many amateur naturalists in England were eager to test the viability of entombed toads. Usually, they put a toad in a flowerpot, sealed it with plaster or mortar, and buried it in their gardens. After waiting for a period of time, the pot was unearthed and the toad freed. Usually, in these experiments, the animal turned out to be alive and in good health. Even zoologist Edward Jesse’s toad, which had been closed up in a flowerpot for 20 years, jumped out vigorously when the pot was opened. These experiments were often widely publicised in the local newspapers, and it was concluded that toads could live forever if left alone in a small cavity without anything to eat or drink.

Dr William Buckland, Professor of Geology at Oxford and later Dean of Westminster, planned a rigorous set of experiments to determine the reality of the toad-in-the-hole phenomenon once and for all. In a block of coarse limestone, 12 circular cells were prepared, each about one foot (30cm) deep and 5in (13cm) in diameter. Six large toads and six smaller ones were put in these holes. The cells were all sealed with circular plates of glass. Twelve smaller holes were prepared in a block of sandstone, provided with toads and sealed with glass plates in the same manner. After a double cover of glass and clay had been placed over each block of stone, the blocks were buried in Professor Buckland’s garden under 3ft (90cm) of earth. A year later, in December 1826, the blocks of stone were dug up and examined. All the toads in the sandstone block were dead and decayed; all the small toads in the limestone block were also dead. To his amazement, Buckland found that the larger toads in the porous limestone block were still alive, and that two of them had even gained weight. The block of stone was resealed and the mute prisoners buried alive a second time. Buckland examined them several times during the second year, to see if they hibernated, but this was not the case; they were all awake, sitting in their cells, but their emaciation increased each time the stone was unearthed, until finally they were all dead.

The results of Buckland’s experiment made him doubt the reality of the toad-in-the-hole phenomenon. It was now proven that these animals could not survive in the compact sandstone, which did not admit air to their cells. Even in the porous limestone, they starved to death within two years. The majority of Buckland’s contemporaries agreed with his conclusions, and thus the zoological establishment permanently lost faith in the entombed toad phenomenon.

But in spite of Buckland’s careful preparations, his experiments have certain important flaws, and there is good reason to doubt whether they really disprove the toad-in-the-hole legend. Since Buckland had been collecting toads for some time, his specimens may just have come out of hibernation and thus not have been strong. He also disregarded the fact that the toad’s metabolism and disposition to hibernate is temperature dependent; no record was kept of the climatic conditions during the experimental period. It may also have been unwise of him to dig up the slab of stone at regular intervals, thus disturbing the toad’s attempts at reaching a hibernating state, and exposing them to the light. Buckland’s theory that insects had gained entry through a crack in the glass pane does not seem particularly likely. If the toad that had gained in weight had devoured such a considerable number of insects, its cell would have been likely to contain excrement with the shell parts of these insects, but even an observer as astute as William Buckland didn’t notice this. An alternative explanation of the animal’s weight gain may be that it was dehydrated when put in its cell, and later absorbed moisture through the skin.

The Blois Toad

In June 1851, some French workmen were digging a deep well near Blois. They found a large flintstone, which was split in two by a hard blow with a pickaxe. In the middle of the stone sat a large toad, which jumped out and started to crawl away. It was captured by the workmen, who carried it in triumph to the Society of Sciences in Blois. Both the toad and the stone were put in a damp cellar, and embedded in moss. The French Academy of Sciences appointed a committee of experts to look into the case, chaired by the veteran herpetologist Professor André Duméril. Although he was a convinced sceptic and much inclined to disbelieve the toad-in-the-hole phenomenon altogether, he couldn’t help being impressed by the way the toad’s body exactly fitted the cavity in the flint. Following their investigation, Professor Duméril and his colleagues had to declare that they could find no evidence whatsoever of fraud, and that the toad had apparently been living and growing within the flint for a prolonged period of time, cut off from the outside world. They confessed themselves completely baffled.

When Professor Duméril’s paper was published in the Academy’s Comptes Rendus, several academicians suspected that the whole thing was an imposture, instigated perhaps by the workmen who had pretended to find the toad. They suggested that the toad should have been killed and dissected as soon as it was taken out of the stone; if incompletely digested insects were found within its intestinal canal, it was of course highly unlikely that it had spent many years inside the flint without food. At the next session of the Academy, both Duméril and his opponents were thanked for their contributions to zoology, but the Academy did not make any kind of official statement with regard to the Blois toad.

Toad Fever

In the mid-1800s, Britain’s fascination with the toad-in-the-hole reached the height of mass hysteria. Every year, several new cases were reported, both in scientific periodicals and daily newspapers. In his journal All the Year Round, Charles Dickens compared the toad-in-the-hole with the equally controversial phenomenon of toad showers: “Not content with puzzling me with their subterraneous doings, these provoking reptiles are said to come down from the skies in showers.” The British public, whose knowledge of natural history was otherwise unremarkable, knew at least two things about toads: they could fall from the clouds in showers, and they could live thousands of years embedded in solid stone.

In the autumn of 1862, the Great International Exhibition was opened in Cromwell Road, London (intially funded from the profits of the original 1851 Great Exhibition). One section contained geological specimens from English and Welsh mines, among them a large block of coal from the mine of Cwmtillery, which, when cloven in two, had been found to contain a living frog. Attendees rejected the curiosities of three continents in favour of the Welsh frog-in-the-coal. In a sermon, a clergyman urged all Englishmen to watch this frog with reverence: it was one of the creatures first created by God, and had “breathed the same air as Noah and sported in the limpid streams in which Adam bathed his sturdy limbs”.

The surgeon Frank Buckland, son of William Buckland, shared his father’s interest in the toad-in-the-hole problem. To debunk the newspaper reports about this ‘antediluvian’ frog, he obtained permission to examine it closely. It seemed to be a young frog rather than a fully-grown specimen. The alleged century-long stay in the block of coal had not diminished its vivacity, and it jumped merrily about. Some sceptics even suggested that the exhibitor of the frog should be charged with fraud and imposture. Meanwhile, members of the public defended the frog’s honour in no uncertain terms, and more new cases of toads-in-the-hole were reported than ever before. Many of these seem rather unconvincing; one newspaper article came from a man who had found a live toad inside his marble mantelpiece, when it had fallen and broken in two.

Some commentators have marvelled at this passion for entombed toads in mid-19th-century Britain: this obscure topic seems to have been given more attention in the newspapers than any other biological problem. One reason might have been that it played a part in the debate about Darwinism. Certain conservative clergymen enrolled the entombed toads in their ranks to fight Darwin’s blasphemous theories. They considered the toad-in-the-hole as one of the firmest arguments that a universal deluge had really happened. According to their version of geology, the rocks had formed later from sedimentary matter left by the deluge; certain toads, which had survived the Flood, had thus been encased in stone and lived there for thousands of years.

Indeed, many of the British toads-in-the-hole were described by clergymen. In April 1865, some workmen claimed to have found a live toad in a large limestone block. The cavity was no larger than its body, and presented the appearance of being a cast around it. The toad’s eyes shone with unusual brilliance, and its mouth was completely closed. The Rev Robert Taylor, Rector of St Hilda’s Church, Hartlepool, adopted the toad and gave it a home in the Hartlepool Museum. He claimed that the toad was 36 million years old, and that it had been sitting in its hole since the stone was first formed. Both the toad and the bold geologist-parson became national celebrities. But when a party from the Manchester Geological Society visited Hartlepool to see the toad and inspect its hole in the block of stone, one of them could feel marks of a chisel! He accused the collier who claimed to have found the toad of having perpetrated this fraud. The man first insisted that he was telling the truth, but later ignominiously withdrew. After this exposure, the Rector took back his daring statements about the antediluvian toad, but this did not prevent him from being much laughed at during one of the Manchester Geological Society’s monthly meetings.

An Enduring Anomaly

There are more than 210 cases of frogs or toads found inside stones, lumps of coal, or within the trunks of large trees – from Europe, the United States, Canada, Africa, New Zealand and the West Indies. The earliest are from the late 15th century, the latest occurred in Australia and New Zealand in the early 1980s [FT40:7]. On more than one occasion, the toads were seen by several independent witnesses. Sometimes these people – like the Swedish master builder – were entirely ignorant that similar prodigies had ever been described. After a close study of some of the best attested cases of entombed toads, the immediate conclusion is that the legend of entombed toads cannot have been based on imagination alone. Certain remarkable details about the subterranean toads and frogs often recur: the mouth covered by a viscous membrane, the skin darker than usual, and the eyes shining brightly.

During the heyday of the toad-in-the-hole, many specimens were presented to various museums, but these relics of the credulous Victorian era have been discarded by latter-day curators. The world’s only remaining entombed toad now resides at the Booth Museum of Natural History in Brighton [FT81:30–31]. It was donated by the amateur naturalist Charles Dawson in 1901, and consists of an oval, hollow flint nodule containing a desiccated toad. Dawson said that he had been given it by some workmen, who had noticed that the stone seemed lighter than expected, and broken it with a spade to see what was inside. A cavity inside appeared to have formed around an ancient sponge. There was a connection between the hole inside the nodule and the outside world, by way of the narrow channel once occupied by the sponge’s stem; this can still be seen in the Brighton preparation. Dawson suggested that the toad had crawled in through this aperture when it was very young. In some way, it was able to procure food; perhaps some insects and larvæ chose the same way in. The toad had then grown too large to escape through the narrow passage and had starved to death in its stony prison. If the workmen had split the stone before the animal had died, it would have joined the ranks of the living toads-in-the-hole. Since the Brighton stone nodule is not the only one formed around a sponge, Dawson suggested that his explanation could be extended to cover quite a few of the other entombed toads, and even provide a tentative explanation of the phenomenon.

There is, however, a serious problem. The name of Charles Dawson has been blackened by his involvement in the most notorious scientific forgery of all time: the Piltdown scandal, in which a faked anthropoid skull was claimed to belong to Darwin’s ‘missing link’ between human and ape [FT62:24–30]. In his 2003 book Piltdown Man, the archæologist Dr Miles Russell has presented the most comprehensive analysis to date of Dawson’s weird activities, demonstrating that over a period of more than 20 years, he was guilty of wholesale scientific fraud and plagiarism, culminating in the Piltdown hoax. His pretended ‘discoveries’ were often of a spectacular nature, just like the toad-in-the-hole.

Nor can the toad itself be taken at face value. Comparison with the original 1901 photographs demonstrates that it has shrunk in size since then, suggesting that it had not been dead for very long when submitted to the museum. This supports the hypothesis that Dawson had found the right flint and dried the toad to concoct one of his hoaxes. Another suspicious circumstance is that it succumbed neither to mould nor to fungal attack, but to mummification. As for Dawson’s explanation of the entombed toad phenomenon, it must be pointed out that it is far from natural for a young toad to spend much time on the dry chalk. And if the flint nodule had by some strange coincidence ended up in the vicinity of a stream, why had the toad not just rotted once it died?

The entombed toad is an anomaly in the true sense of the word. The phenomenon is not only irrational but completely inexplicable. There appears to be no reasonable explanation for this remarkable series of observations of toads and frogs discovered inside blocks of stone. The counter-arguments proposed here are hardly sufficient to exorcise these prematurely buried toads, which have led their own slumbering, accursed half-life outside the boundaries of biology for several centuries.

It is a fitting final tribute to the toads-in-the-hole to quote from Dante Gabriel Rossetti’s poem Jenny, written in 1870:

Like a toad within a stone

Seated while time crumbles on;

Which sits there since the earth was cursed

For man’s transgression at the first;

Which, living through all centuries,

Not once has seen the sun arise;

Whose life, to its cold circle charmed,

The earth’s whole summers have not warmed;

Which always – whitherso the stone

Be flung – sits there, deaf, blind, alone…