Tigers, the Ultimate Guide, Two Brothers Press, ed, V. Thapar, 2004

One evening in the 1870s, George Romanes was talking to Charles Darwin about "the sublime." Darwin said he had felt it most on the summit of the Cordillera, looking at "the magnificent prospect all around." They talked of other things and went to bed. Romanes, a devoted Darwin disciple, fell comfortably asleep. But at one in the morning the great man, a fairly elderly great man by now, put on dressing gown and slippers and gently opened his friend's door.

"I have been thinking over our conversation," he said. "It has occurred to me I was wrong in telling you I felt most of the sublime on top of the Cordillera. I am quite sure I felt it even more in the forests of Brazil. I am sure now, that I felt most sublime in the forests."

But in the Origin of Species, this man who felt most sublime in the forests does not mention their sublimest inhabitant, save for a passing reference on predation and numbers in Chapter 3: "The amount of food for each species of course gives the extreme limit to which each can increase; but very frequently it is not the obtaining food, but the serving as prey to other animals, which determines the average numbers of a species. . . . In some cases, as with the elephant and rhinoceros, none are destroyed by beasts of prey: even the tiger in India rarely dares to attack a young elephant protected by its dam."

The reasons why Darwin did not dwell on tigers speak to important aspects of him and his work-to his particular pathways of mind and historical accidents of his life but also the kind of inquiry his work was, in which he laid out his insights on evolution and biodiversity.

Alexander von Humboldt, South America, and "Tangle"

The obvious reason is that he was focused on the wrong continent. His starting point was the Beagle's voyage to South America, 1831-1836. Even in his last year at Cambridge, Darwin had an imagination that was passionately imprinted with the South American jungle. He read Personal Narrative by Alexander von Humboldt (1769-1859), one of the greatest of the "romantic" scientists-imaginative, committed, subjective-who wrote vividly and very personally about extraordinary experiences. This book, along with J. Herschel's Introduction to the Study of Natural History, stirred up in the young Darwin "a burning zeal to make even the most humble contribution to the noble structure of Natural Science." He was especially fired by Humboldt's description of Tenerife. In 1831, before setting foot on the Beagle, he wrote to his sister Caroline, "My head is running about the Tropics. In the morning I go and gaze at palm trees in the hothouse and come home and read Humboldt. My enthusiasm is so great that I can hardly sit still in my chair. Sandy dazzling plains and gloomy, silent forests are alternately uppermost in my mind."

He found tropical vegetation even better in the leaf than on the page. When he met it on the Cape Verde Islands he wrote in his journal: "Here I first saw the glory of tropical vegetation. Tamarinds, bananas and palms were flourishing at my feet. I expected a good deal, for I had read Humboldt's descriptions and I was afraid of disappointments. How utterly vain such fear is, none can tell but those who have experienced what I today have,  .treading on volcanic rocks, hearing the notes of unknown birds, seeing new insects fluttering about still newer flowers."

Tellingly, in this entry describing his first contact with tropical vegetation, he records two things: both the external data and his own response to it. This combination was the wellspring of his work. "It is not only the gracefulness of their forms," he wrote, "or the novel richness of their colors, it is the numberless and confusing associations that rush together on the mind. It has been for me a glorious day, like giving to a blind man eyes." Or like, you could say, that moment when a poet or painter finds his or her true subject. For Darwin's deepest subject was the thrill of interaction between his own mind and the natural world outside. "During the five years of my voyage," he wrote later to his fiancée, "which may be said to be the commencement of my real life, the whole of my pleasure was derived from what passed in my mind whilst admiring views by myself, traveling across wild deserts or glorious forests, or pacing the deck of the poor little Beagle at night." His mind responding to those forests was, he said, "a chaos of delight."

For the next twenty years he worked out the fruits of that chaos and delight in a quiet Kent meadow, but the wild tropical original was always there, basis of his vision into biodiversity and the intense pleasure he took in it. A word he often used for it was "tangle." "Walked along a brook flowing between huge granite blocks," he says, exploring a Brazilian forest in June 1832. "No art could depict so stupendous a scene. The decaying trunks of enormous trees scattered about formed in many places natural bridges; beneath and around them the damp shade favored the growth of fern and palm trees. . . . Even by creeping, I could not penetrate the entangled mass of the living and dead vegetation."

By "tangle" he meant the whole mixed-up self-perpetuating wildness of plants and animals interacting with one another-the tangle on which tigers depend, without which no wild tiger can live.

This tangle dominates the final paragraph of the Origin of Species, where Darwin's jungle insight is projected onto modest British woodland: "It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us." But, though Darwin always had this intricate tangle in mind, his business was with origin, cause, and process; namely, how this tangle came to be.

Origin, Process, and the Apparently Insignificant

Here is another reason for not much mentioning tigers: tigers are very much the end result of a process. Darwin himself would not have called them the end result but the latest result: he always insisted that evolution was continuing and might go any direction in the future. Still, as I understand it, though there is dispute about whether the Panthera genus is the absolute latest of feline developments, it does come pretty far along the road, whereas Darwin focused on smaller, humbler wonders that suggested to him insights into origin or long process. Earthworms, plankton, barnacles, bumblebees, the insect-eating sundew (Drosera), and finches' beaks: he built his theories on the intricacies of these apparently insignificant things, as well as on their relations to "higher" things and on the universal laws these relationships suggested. You could never call a tiger insignificant.

On the Beagle, Darwin thrilled to great scenic visions. He may have felt most sublime in the forests, but on the Andean Cordillera he marveled at "the profound valleys, wild broken forms, heaps of ruins piled up during the lapse of ages, the bright colored rocks contrasted with the quiet mountains of Snow, which together produced a scene I never could have imagined." And yet, while collecting and making notes, he also thrilled to the minutest details of individual organisms. He brought the same strenuous wonder to a forest as to the hair on a single plant. His characteristic mental move was from the physically tiny to the universal. Walking near Socego in Brazil, he commented, "If the eye is turned from the world of foliage above, to the ground, it is attracted by the extreme elegance of the leaves of numberless species of ferns and mimosas. . . . Wonder, astonishment and sublime devotion fill and elevate the mind."

Twenty years later, out for a walk near the end of writing the Origin of Species and anxious to discuss the way red ants enslaved black ones, he met a trail of red ants migrating from one nest to another, carrying black ants. After experiments in prizing their burdens off them, he settled down to watch one particular ant. A tramp came along; Darwin paid him a shilling to watch another ant. The two of them squatted, shuffled, and kept pace with their ants. They heard a carriage trotting up, slowing to a walk as the coachman saw them in the road. "You mustn't look up," Darwin told the tramp. They stayed squatting, watching, but Darwin's ant reached a bare place just as the carriage passed him. He glanced up a second and saw a coach full of people gazing at him and the tramp with open mouths. Then he went back to his ant.

He pondered not only the behavior of miniscule creatures but their effects. On Keeling Island, in the Indian Ocean, he saw surf battering the windward coast. "The ocean throwing its waters over the broad reef," he said, appears an invincible, all-powerful enemy, yet we see it resisted and even conquered by means which at first seem most weak and inefficient. It is not that the ocean spares the rock of coral; the great fragments scattered over the reef, and accumulated on the beach, plainly bespeak the unrelenting power of its waves. . . . Yet these low, insignificant coral islets stand and are victorious: for here another power, as antagonist to the former, takes part in the contest. The organic forces separate the atoms of carbonate of lime one by one from the foaming breakers, and unite them into a symmetrical structure. Let the hurricane tear up its thousand huge fragments; what will this tell against the accumulated labor of myriads of architects at work night and day, month after month?

After the description comes, as always, the moral: "Thus do we see the soft and gelatinous body of a polypus, through the agency of the vital laws, conquering the great mechanical power of the waves of an ocean, which neither the art of man, nor the inanimate works of nature could successfully resist."

He gloried in rain forest but saw rainbow beauties in plankton, too: "I am quite tired having worked all day at the produce of my net. The number of animals that the net collects is very great. . . . Many of these creatures so low in the scale of nature are most exquisite in their forms and rich colors. It creates a feeling of wonder that so much beauty should be apparently created for so little purpose." In the East Falkland Islands, he commented on the "immense quantity and number of kinds of organic beings intimately connected with the kelp. . . . I can only compare these great forests to terrestrial ones in the most teeming part of the tropics; yet if the latter in any country were to be destroyed, I do not believe nearly the same number of animals would perish in them as would happen in the case of kelp. (I refer to numbers of individuals as well as kinds.) All the fishing quadrupeds and birds (and man) haunt the beds, attracted by the infinite number of small fish which live amongst the leaves."

He uses his tangle image for watery as well as land forests: "On shaking the great entangled roots, it is curious to see the heap of fish, shells, crabs, sea-eggs, cuttle-fish, star fish, Planariae, Nereidae, which fall out. . . . One single plant form is an immense and most interesting menagerie. If this Fucus were to cease living, with it would go many: the seals, cormorants and certainly the small fish, and then sooner or later the Fuegian man must follow."

If, unlike Darwin, you started from the most beautiful and significant of higher animals, where on earth (or out of it) would you end? The tiger was, as it were, the summit that Darwin was working toward.

Personal Observation

A third reason why Darwin barely mentioned tigers is that he never studied them. Inspired by Humboldt's Personal Narrative and honoring the "personal" of Humboldt's title, he worked from close personal observation. He was not at all against the higher mammals. At home, his dogs and babies were always under the spotlight, foci of his scrutiny, questioning, and theory. Despite the constant glide of his own mind into theory, he believed no one had the right to examine the question of species who had not minutely described many himself, and he did this constantly in later life all over the house and garden. His son Horace helped with the study of earthworms; his daughter Etty wrote labels for shells on the backs of his barnacle notes. Barnacles were so pervasive in the house for a time that one small son was overheard asking a friend, "What does your father do to his barnacles?"

But it was on the Beagle that Darwin trained himself to study and think with what he saw around him. He wrote in his journal every day, taking "much pains in describing carefully and vividly all I had seen." He learned to observe among plankton and rock, acquiring a "habit of energetic industry and of concentrated attention to whatever I was engaged in. Everything about which I thought or read was made to bear directly on what I had seen or was likely to see. This habit of mind was continued during the five years of the voyage. I feel sure that it was this training which has enabled me to do whatever I have done in science."

There were not many tigers on board-but he would have been thrilled to observe them. A remark in one of his Metaphysical Notebooks gives some idea what he felt about them. He is considering the pleasures of imagination, how trains of thought in response to landscape vary from person to person. "My pleasure in Kensington Gardens," he writes in August 1838, "has often been greatly excited by looking at trees [as] great compound animals united by wonderful & mysterious manner. There is much imagination in every view. If one were admiring one in India & a tiger stalked across the plains, how ones [sic] feelings would be excited, & how the scenery would rise." He wrote this while living in London, in Great Marlborough Street, working out his first sketch of evolutionary theory, consciously tackling what he called the "mystery of mysteries." He then kept this sketch in a drawer, for many years.

During that London period, he often visited the Zoological Gardens where there was, by then, a captive tiger. A tigress, the first tiger representative exhibited at the London Zoo, was presented to it on June 8, 1829, and tigers have been shown there continuously ever since. But Darwin could not observe them in the wild, and his insights came from what he studied-though, according to his son Francis, he also said no one could be a good observer unless he was an active theorizer, too. "It naturally happened," said Francis, "that many untenable theories occurred to him." But he always tested them. "He was willing to test what would seem to most people not at all worth testing. These rather wild trials he called  'fool's experiments,' and enjoyed extremely." These experiments included stringing his children through the grass to plot the flight path of bumblebees and asking Francis to play the bassoon to earthworms to see if they could hear. Many experiments went no further; but many others did prove their theories. Etty helped her father breed ninety-three varieties of pigeon that he skeletonized in the kitchen to prove they all descended from the African rock pigeon. The resultant passage in chapter 1 is the only part of the Origin of Species of which the publisher's first reader approved. Everyone loves pigeons, he said. Keep that bit, and throw the rest away. (Luckily, John Murray ignored his reader and went with evolution.)

The historical accidents of Darwin's life meant that he spent five years on a voyage and the following twenty very retiringly, mainly in Kent. So though tropical tangle was his image of interrelatedness, he worked out the insights gained from it in a very different setting. The famous pollination example in the Origin of Species, from which modern understanding of biodiversity evolved, came from observing long grass in his garden. He saw that the only bees to visit red clover were bumblebees: others could not reach the nectar. So, he suggested, if bumblebees became extinct in England, red clover would become rare or disappear. But the number of bumblebees depends on that of field mice, who destroy their nests; and their numbers depend on the number of cats. So the numbers of cats in a neighborhood may well determine the wildflowers that grow in it.

Grandeur Is in the Mind

In 1958, to celebrate the hundred years since the theory of evolution was announced, two of Darwin's granddaughters-my grandmother Nora Barlow and her cousin Margaret Keynes-decided to restore the garden where Darwin worked out his tropics-won ideas. My cousin Randal Keynes, Margaret's grandson, is helping English Heritage grow the garden back. From photographs, they have identified specific climbers draggling round the veranda; from records, they have restored Darwin's greenhouses. They have grown back the "Sandwalk," where Darwin solved problems on his constitutional saunters, grading his intellectual workings-out as one-stone, two-stone, or three-stone problems, adding a stone to a cairn after every lap.

But one thing is hard for English Heritage to replicate: a fact about Darwin that touches on my last reason why he did not much mention tigers. Darwin was instinctively ungrand, and you cannot get much grander, zoologically, than a tiger. The house and garden are on show now but were very much not a showplace then. They were pretty untidy-something English Heritage is reluctant to be Darwinian about. Lawn and drawing room were strewn with children's paraphernalia, picnic rugs, and earthworm experiments. The local flower society gave up on Darwin. Unlike most Kent gentry, he had greenhouses because he worked in them, not because he wanted to win prizes. He did not want to show plants but to study them and then move on to the next thing. For to Darwin, grandeur came not so much from outward structure but from inner vision. He felt sublime in forests, but the grandeur lay not only in their physical impressiveness but in the imagination's response to it, the intellect's leap from small ferny details to understanding the universal processes that made the whole. He once said that his deepest pleasure in the Galápagos had been observing and then understanding. It lay in the insight, "the discovery of the singular relations of the animals and plants inhabiting the several islands." What was grand was not the writhing interrelated vegetation itself but one's own intuitive grasp of that interrelatedness and how it came to be.

As he began developing his theory of evolution after the voyage, he wrote lyrically, in Notebook D, of the grandeur in understanding cause: "What a magnificent view one can take of the world. Astronomical causes, modified by unknown ones, cause changes in geography and changes in climate superadded to change of climate from physical causes. These superinduce changes in form in the organic world, as adaptation, and these changing affect each other, and their bodies, by certain laws of harmony keep perfect in these themselves. Instincts alter, reason is formed, and the world peopled with myriads of distinct forms from a period short of eternity to the present time, to the future." This view of nature, he says, is "far grander" than the defenses against the chronological implications of fossils, mounted by the religion of the day: "the idea from cramped imagination that God (warring against those very laws he established in all organic nature) created the rhinoceros of Java and Sumatra, that since the time of the Silurian he has made a long succession of vile molluscous animals."

Darwin always had a vivid sense of nature's beauty. But to him, grandeur lay in realizing how ruthlessly it came into being and will go on changing, via survival of the fittest: "You can understand the true conditions of life only if you use your imagination to hold on to a sense of the ruthlessness of the natural forces that could waste the bright surface." This is Darwin's paradox: the beauty and the brightness are bound to the cruelty that created them.

Behind all this is a ruthlessly intellectual notion of the grand. "Grand" lies in the causes of tangle and in apprehending the complexities of action and reaction behind those causes. "When we look at the plants and bushes clothing an entangled bank," Darwin said, "we are tempted to attribute their proportional numbers and kind to what we call chance. But how false a view is this! Everyone has heard that when an American forest is cut down, a very different vegetation springs up; but it has been observed that the trees now growing on the ancient Indian mounds in the Southern United States, display the same beautiful diversity and proportion of kinds as in the surrounding virgin forests."

So Darwin does not care about the difference between pristine and secondary forest. What he is gunning for is understanding the process by which both are made: "What a struggle between the several kinds of trees must here have gone on during long centuries, each annually scattering its seeds by the thousand; what war between insect and insect-between insects, snails and other animals with birds and beasts of prey-all striving to increase, and all feeding on each other or on trees or their seeds and seedlings, or on the other plants which first clothed the ground and thus checked the growth of the trees!" Intricacy, complexity: he wonders at them over and over. He did not, of course, envisage a world of genetically engineered simplicity, where complexity itself might be dangerously lost: "Throw up a handful of feathers, and all must fall to the ground according to definite laws; but how simple is this problem compared to the action and reaction of the innumerable plants and animals which have determined, in the course of centuries, the proportional numbers and kinds of trees now growing on the old Indian ruins!"

At the end of the Origin of Species he returns to the "entangled bank": to how the richness of the natural world, this beautiful tangle, is the outcome of the struggle for existence. The "bright surface" and "tangle" were created by "laws acting around us": growth with reproduction; inheritance which is also implied by reproduction; variability from the indirect and direct action of the external conditions of life, and from use and disuse; a ratio of increase so high as to lead to a struggle for life, and as a consequence to natural selection, entailing divergence of character and the extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows.

Grandeur crops up again when he draws the conclusion: "There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved."

"Forms the most beautiful and wonderful"

Tigers, at the top of every bright surface and forest tangle on their continent, were among the highest of such forms and are the perfect goal for Darwin's key insights of the Origin of Species (for tigers came out on top, or have done until now, in survival of the fittest), and of biodiversity, since tigers and their forests depend completely on the intricate interrelatedness of which Darwin wrote with such wonder. Charles Darwin did not need to write explicitly about tigers in the Origin of Species. In a sense, he was writing about them all the time. They are the evolved paradigm of what he was working toward. Tigers are what Darwin wanted to explain.