As an effect of this principle, we seldom find closely allied species of animals or plants living together, but often in distinct though adjacent districts where the conditions of life are somewhat different. Thus we may find cowslips (Primula veris) growing in a meadow, and primroses (P. vulgaris) in an adjoining wood, each in abundance, but not often intermingled. And for the same reason the old turf of a pasture or heath consists of a great variety of plants matted together, so much so that in a patch little more than a yard square Mr. Darwin found twenty distinct species, belonging to eighteen distinct genera and to eight natural orders, thus showing their extreme diversity of organisation. For the same reason a number of distinct grasses and clovers are sown in order to make a good lawn instead of any one species; and the quantity of hay produced has been found to be greater from a variety of very distinct grasses than from any one species of grass.
It may be thought that forests are an exception to this rule, since in the north-temperate and arctic regions we find extensive forests of pines or of oaks. But these are, after all, exceptional, and characterise those regions only where the climate is little favourable to forest vegetation. In the tropical and all the warm temperate parts of the earth, where there is a sufficient supply of moisture, the forests present the same variety of species as does the turf of our old pastures; and in the equatorial virgin forests there is so great a variety of forms, and they are so thoroughly intermingled, that the traveller often finds it difficult to discover a second specimen of any particular species which he has noticed. Even the forests of the temperate zones, in all favourable situations, exhibit a considerable variety of trees of distinct genera and families, and it is only when we approach the outskirts of forest vegetation, where either drought or winds or the severity of the winter is adverse to the existence of most trees, that we find extensive tracts monopolised by one or two species. Even Canada has more than sixty different forest trees and the Eastern United States a hundred and fifty; Europe is rather poor, containing about eighty trees only; while the forests of Eastern Asia, Japan, and Manchuria are exceedingly rich, about a hundred and seventy species being already known. And in all these countries the trees grow intermingled, so that in every extensive forest we have a considerable variety, as may be seen in the few remnants of our primitive woods in some parts of Epping Forest and the New Forest.
Among animals the same law prevails, though, owing to their constant movements and power of concealment, it is not so readily observed. As illustrations we may refer to the wolf, ranging over Europe and Northern Asia, while the jackal inhabits Southern Asia and Northern Africa; the tree-porcupines, of which there are two closely allied species, one inhabiting the eastern, the other the western half of North America; the common hare (Lepus timidus) in Central and Southern Europe, while all Northern Europe is inhabited by the variable hare (Lepus variabilis); the common jay (Garrulus glandarius) inhabiting all Europe, while another species (Garrulus Brandti) is found all across Asia from the Urals to Japan; and many species of birds in the Eastern United States are replaced by closely allied species in the west. Of course there are also numbers of closely related species in the same country, but it will almost always be found that they frequent different stations and have somewhat different habits, and so do not come into direct competition with each other; just as closely allied plants may inhabit the same districts, when one prefers meadows the other woods, one a chalky soil the other sand, one a damp situation the other a dry one. With plants, fixed as they are to the earth, we easily note these peculiarities of station; but with wild animals, which we see only on rare occasions, it requires close and long-continued observation to detect the peculiarities in their mode of life which may prevent all direct competition between closely allied species dwelling in the same area.
The Ethical Aspect of the Struggle for Existence.
Our exposition of the phenomena presented by the struggle for existence may be fitly concluded by a few remarks on its ethical aspect. Now that the war of nature is better known, it has been dwelt upon by many writers as presenting so vast an amount of cruelty and pain as to be revolting to our instincts of humanity, while it has proved a stumbling-block in the way of those who would fain believe in an all-wise and benevolent ruler of the universe. Thus, a brilliant writer says: "Pain, grief, disease, and death, are these the inventions of a loving God? That no animal shall rise to excellence except by being fatal to the life of others, is this the law of a kind Creator? It is useless to say that pain has its benevolence, that massacre has its mercy. Why is it so ordained that bad should be the raw material of good? Pain is not the less pain because it is useful; murder is not less murder because it is conducive to development. Here is blood upon the hand still, and all the perfumes of Arabia will not sweeten it."[13]
Even so thoughtful a writer as Professor Huxley adopts similar views. In a recent article on "The Struggle for Existence" he speaks of the myriads of generations of herbivorous animals which "have been tormented and devoured by carnivores"; of the carnivores and herbivores alike "subject to all the miseries incidental to old age, disease, and over-multiplication"; and of the "more or less enduring suffering," which is the meed of both vanquished and victor. And he concludes that, since thousands of times a minute, were our ears sharp enough, we should hear sighs and groans of pain like those heard by Dante at the gate of hell, the world cannot be governed by what we call benevolence.[14]
Now there is, I think, good reason to believe that all this is greatly exaggerated; that the supposed "torments" and "miseries" of animals have little real existence, but are the reflection of the imagined sensations of cultivated men and women in similar circumstances; and that the amount of actual suffering caused by the struggle for existence among animals is altogether insignificant. Let us, therefore, endeavour to ascertain what are the real facts on which these tremendous accusations are founded.
In the first place, we must remember that animals are entirely spared the pain we suffer in the anticipation of death—a pain far greater, in most cases, than the reality. This leads, probably, to an almost perpetual enjoyment of their lives; since their constant watchfulness against danger, and even their actual flight from an enemy, will be the enjoyable exercise of the powers and faculties they possess, unmixed with any serious dread. There is, in the next place, much evidence to show that violent deaths, if not too prolonged, are painless and easy; even in the case of man, whose nervous system is in all probability much more susceptible to pain than that of most animals. In all cases in which persons have escaped after being seized by a lion or tiger, they declare that they suffered little or no pain, physical or mental. A well-known instance is that of Livingstone, who thus describes his sensations when seized by a lion: "Starting and looking half round, I saw the lion just in the act of springing on me. I was upon a little height; he caught my shoulder as he sprang, and we both came to the ground below together. Growling horribly close to my ear, he shook me as a terrier-dog does a rat. The shock produced a stupor similar to that which seems to be felt by a mouse after the first shake of the cat. It causes a sort of dreaminess, in which there was no sense of pain or feeling of terror, though I was quite conscious of all that was happening. It was like what patients partially under the influence of chloroform describe, who see all the operation, but feel not the knife. This singular condition was not the result of any mental process. The shake annihilated fear, and allowed no sense of horror in looking round at the beast."
This absence of pain is not peculiar to those seized by wild beasts, but is equally produced by any accident which causes a general shock to the system. Mr. Whymper describes an accident to himself during one of his preliminary explorations of the Matterhorn, when he fell several hundred feet, bounding from rock to rock, till fortunately embedded in a snow-drift near the edge of a tremendous precipice. He declares that while falling and feeling blow after blow, he neither lost consciousness nor suffered pain, merely thinking, calmly, that a few more blows would finish him. We have therefore a right to conclude, that when death follows soon after any great shock it is as easy and painless a death as possible; and this is certainly what happens when an animal is seized by a beast of prey. For the enemy is one which hunts for food, not for pleasure or excitement; and it is doubtful whether any carnivorous animal in a state of nature begins to seek after prey till driven to do so by hunger. When an animal is caught, therefore, it is very soon devoured, and thus the first shock is followed by an almost painless death. Neither do those which die of cold or hunger suffer much. Cold is generally severest at night and has a tendency to produce sleep and painless extinction. Hunger, on the other hand, is hardly felt during periods of excitement, and when food is scarce the excitement of seeking for it is at its greatest. It is probable, also, that when hunger presses, most animals will devour anything to stay their hunger, and will die of gradual exhaustion and weakness not necessarily painful, if they do not fall an earlier prey to some enemy or to cold.[15]
Now let us consider what are the enjoyments of the lives of most animals. As a rule they come into existence at a time of year when food is most plentiful and the climate most suitable, that is in the spring of the temperate zone and at the commencement of the dry season in the tropics. They grow vigorously, being supplied with abundance of food; and when they reach maturity their lives are a continual round of healthy excitement and exercise, alternating with complete repose. The daily search for the daily food employs all their faculties and exercises every organ of their bodies, while this exercise leads to the satisfaction of all their physical needs. In our own case, we can give no more perfect definition of happiness, than this exercise and this satisfaction; and we must therefore conclude that animals, as a rule, enjoy all the happiness of which they are capable. And this normal state of happiness is not alloyed, as with us, by long periods—whole lives often—of poverty or ill-health, and of the unsatisfied longing for pleasures which others enjoy but to which we cannot attain. Illness, and what answers to poverty in animals—continued hunger—are quickly followed by unanticipated and almost painless extinction. Where we err is, in giving to animals feelings and emotions which they do not possess. To us the very sight of blood and of torn or mangled limbs is painful, while the idea of the suffering implied by it is heartrending. We have a horror of all violent and sudden death, because we think of the life full of promise cut short, of hopes and expectations unfulfilled, and of the grief of mourning relatives. But all this is quite out of place in the case of animals, for whom a violent and a sudden death is in every way the best. Thus the poet's picture of