! i M 1 * I i M ! i I ■' '•i:H!|!M!;ii!'!n!in i' I UW: 't!!l'l' ®ln> B, p. I^ill mibrax-g Vi5 f ;21 BC) This BOOK may be kept out TWO WEEKS ONLY, and is subject to a fine of FIVE CENTS a day thereafter. It is due on the day indicated below: I0%4^A A NATURALIST IN HIMALAYA IN THE HIMALAYA. Frottlts-t>iecs A NATURALIST IN HIMALAYA BY R. W. G. HINGSTON, M.C., M.B., CAPTAIN, INDIAN MKDICAL SERVICE. WITH PLATES AND TEXT FIGURES BOSTON SMALL, MAYNARD & COMPANY, PUBLISHERS. PREFACE This volume is what Its name suggests. It is a record of observations in natural science. It is an endeavour to gather many and varied facts into one common theme. The observations which it describes have been collected at intervals between the years 1914 and 1916 in the Himalayan valley of Hazara. They have been made slowly, gathered intermittently and then arranged with some attempt at order so as to appear in a collected whole. My narrative will fall into different parts in accord- ance as my observations refer to different forms of animal life. I will commence with a brief description of the valley itself in order that the reader may appreciate the more striking geographical features of the district in which the subsequent observations were made. In the next four chapters I will discuss the habits, instincts and general economy of certain species of ants that are to be found everywhere in the valley. I will then pass to a series of observa- tions on the natural history of spiders, especially with regard to the wonderful geometrical powers employed in the construction of their circular snares. In the tenth, eleventh and twelfth chapters I have collected a number of varied facts and sucroestions that relate to the economy of insect life. In the thirteenth and fourteenth chapters I have discussed some matters of 62160 vi PREFACE interest with respect to the mammals and birds of the valley, while in the last chapter I have endeavoured to describe in simple language the essential features of its rocky structure and the sequence of changes through which it has passed in the long lapse of CTeolooical time. My interest has been chiefly directed towards the habits of animals, especially in so far as they relate to the psychology of instinct. The book contains nothing of a pure systematic nature. My object is to give some impression of the more striking mani- festations of life that are to be seen in a Himalayan valley. So many of my observations are concerned with insects and other humble forms that it may be thought I have paid them undue attention when com- pared with my record of the mammals and birds. But it needs only the slightest insight to the works of Nature to see how wonderful she is even in her very simplest types. I have had drawings made of those species to which I have given most attention, and trust that these will add interest to the subject matter of the text. The few photographs of scenery which I have introduced do not in all cases bear directly on the chapters in which they appear. Their object is to give the reader some impression of the rugged features of the Himalaya. I cannot expect that my record is likely to interest any but those who have a special taste for Natural History, and have bestowed some little observation on it. Nevertheless I have endeavoured to express myself in untechnical language, confident that a sub- ject, because it is intelligible, is none the less scientific PREFACE vii or exact. I have not tried to escape from theory, nor have I refrained from forming an hypothesis where it has seemed to be justified by facts. The volumes of reference at my disposal have been few ; and indeed if my work has any merit, it must rest in the fact that almost all it contains has been taken not from the works of others but rather from what Nature in her goodness has thought it fitting to disclose. The Author. April ip20. CONTENTS CHAPTER I A HIMALAYAN VALLEY PAGE Definition of Himalaya — Appearance of the range — District of Ha/^ara — General features of Hazara — Its valleys, hills and forests . . . i CHAPTER n HARVESTING ANTS General habits — Appearance of ant — Sexual forms — Collection of seeds — Effect of heat, cold, shade, rain, darkness — Cessation of toil — Division of labour ............ ii CHAPTER HI SENSES AND INSTINCTS OF HARVESTING ANTS Sense of smell — Sense of direction — Communication — Play and sport — Peacefulness — Mode of defence — Emotions — Economy — Migration — Pliability of instinct — Aberration of instinct — Folly of ants . . 24 CHAPTER IV CARNIVOROUS ANTS Myrmecocysfus setipes — General habits — Division of labour — Food — Sense of smell — Attitude of abdomen — Absence of sympathy — Mode of founding new colony — Intelligence — Folly • 44 CHAPTER V COMMUNICATING AND OTHER ANTS Phidole indica — Mode of attack — Power of communication — Experiments on faculty of communication — Sense of smell — Every individual in nest differs — Division of labour — Attitude of Cremasto^aster — Migra- tions of Acanthokpis — Sexual forms of Camponotus .... 60 CHAPTER VI GEOMETRICAL SPIDERS Home of spider — Species under discussion — Constitution of colonies — Construction of snare — Emission and structure of the first line — Mechanism in construction of radii — Mechanism in hub — Mechanism in temporary spiral — Mechanism in viscid spiral ..... 82 ix CONTENTS CHAPTER VII KUKTHER OliSERVATlONS ON THE C.EOMETRICAL SNARE FAGE Ultimate fate of temporary spiral — Reversal of spiral — Reason of reversal of spiral — Example of plasticity of instinct — Spider's power to estimate tension — Delicacy of sense of touch — Industry of Aratiats — Mode of emission of fdamenl — Economy of spider and destruction of snare — Perfection and imperfection in snare ....... io8 CHAPTER VIII THE INSTINCT OF SPIDERS Spiders and weather — Force of instinct — Repair of well — Experiments to indicate the unswerving force of instinct — Slavery to instinct — Trans- ference to other snares — Spider not entangled in its own snare — Mode of escape — Protective resemblance — Special senses of spiders . .124 CHAPTER IX SHEET-BUILDING SPIDERS Habits of spider and character of snare — Refusal to spin in stormy weather — Mode of capturing prey — Injection of poison — Sense of touch — Function of pedipalps — Force of instinct — Shamming death in spiders and insects — Physical properties of web — Pertinacity of Artana . .150 CHAPTER X OBSERVATIONS ON INSECT LIFE. Mountain dust — Inhabitants of pools — Carnivorous flies — Water-boatmen — Struggle for life — Mentality of fishes — Habits of Ves/>a orientalis — Nest of Polistes — Depredations of Vespa viagnifua — Mimicry in humble-bees — Humble-bees and flowers — Habits of leaf-cutting bees — Instinct of mud-wasp — Instinct of digger-wasps 164 CHAPTER XI BUTTERFLIES, MOTHS AND CICADAS Swallow-tails of Harara — Sexual display — Protective coloration in butter- flies— Butterflies resembling leaves — Protectively-coloured moths — Enemies of butterflies and moths — Instinctive fear of enemies — Rainy season in Hazara — Habits and musical organs of Cicada . . . 196 CHAPTER XII GLOW-WORMS, TERMITES AND SHELLS Habits and luminosity of glow-worms — Their contests with snails — Flight and destruction of termites — Instincts associated with their distribution anil preservation — Shedding of wings — Habits of ant-lions — Notes on the dispersal of shells . . . . . . . . . .218 CHAPTER XIII OBSERVATIONS ON MAMMALS Comparative scarcity of mammals — Observations on flying squirrel — Habits and instincts of Himalayan monkeys — Emotional expression in the leopard — Contentment — Fear — Anger — Distress — Eagerness — Atten- tion— Affection 239 CONTENTS xi CHAPTER XIV ORNITHOLOGICAL OBSERVATIONS PAGE General migration of birds — Distribution and habits of bulhuls — Plasticity of instinct — Paradise flycatchers — The black drongo — Habits of the purple sunbird — Nesting instinct of the whistling thrush, the bnrbct, and the Kashmir martin — Troops of insectivorous birds — Tumbling of birds — Soaring fhght of birds ........ 258 CHAPTER XV GEOLOGICAL SKETCH General features of Hazara — Central granite — Pahuozoic slates — Infra- Triassic series — Triassic limestones — ^Jurassic and Cretaceous — Eocene Nummulitics — Vegetation of Tertiaries — Summary of geological changes — Movements of sand in a mountain stream ..... 279 Index .... 297 LIST OF ILLUSTRATIONS •a(;e 'rontispiece Facing 4 • J » 13 . 24 • 44 • » t 60 • • 68 Facin<; 88 88 IN THE HIMALAYA MAP OF WESTERN HIMALAYA .... THE HARVESTING ANT AND THE CARNIVOROUS ANT A VALLEY IN THE HIMALAYA .... A MOUNTAIN VIEW IN THE HIMALAYA COMMON ANTS OF HAZARA .... EXPERIMENT WITH COMMUNICATING ANT . SPIDERS OF HAZARA ..... DIAGRAM OF THE PARTS OF A GEOMETRICAL SNARE LOSS OF PARALLELISM RESULTING FROM DIVISION OF ONE TURN OF VISCID SPIRAL IN ONE SEGMENT ...... I02 LOSS OF PARALLELISM TIESULTING FROM DIVISION OF ONE TURN OF VISCID SPIRAL IN TWO SEGMENTS ...... IO3 DIAGRAM OF REVERSAL OF SPIRAL IIO REVERSAL OF SPIRAL IN AN ECCENTRIC SNARE . . . .Ill THE HEART OF THE HIMALAYA ..... Facing I24 THE PEAKS UNDER FRESH SNOW . . . . . . ,, 164 CICADA {Platylomia hrevis) . . .-. . . . .212 DRUM OF CICADA . . . . . . . . . .215 DIAGRAM TO SHOW ESSENTIAL PARTS OF MUSICAL ORGAN OF CICADA 2l6 THE FLYING-SQUIRREL Facing 24 1 THE BENGAL MONKEY AND EMOTIONAL EXPRESSION IN THE LEOPARD. (l) CONTENTMENT „ 245 EMOTIONAL EXPRESSION IN THE LEOPARD. (2) FEAR. (3) ANGER ,, 248 EMOTIONAL EXPRESSION IN THE LEOPARD. (4) DISTRESS. (5) EAGERNESS , 252 EMOTIONAL EXPRESSION IN THE LEOPARD. (6) ATTENTION. (7) AFFECTION ........... 256 THE INDIAN PARADISE FLYCATCHER AND NEST . . . ,, 262 THE BROWN-BACKED INDIAN ROBIN AND NEST . . . ,, 267 xii A NATURALIST IN HIMALAYA CHAPTER I A HIMALAYAN VALLEY Definition of Himalaya — Appearance of the range — District of Hazara — General features of Hazara — Its valleys, hills and forests. It would be no easy problem to define the Himalaya, the Abode of Snow. It is a mountain system composed of many ranges whose terminations are unknown. The southern and northern limits of the system are apparent at a glance. To the south it rises direct from the plains of India ; to the north it blends with the lofty plateaux of Thibet and the Pamir. But where would the geographer place its eastern and western ends ? Thirty years ago he would have marked the line of the Indus river as its furthest limit to the west and that of the Brahmaputra as its termination in the east, but such boundaries would scarcely hold to-day. For these are mere arbitrary limits that bear no true relation to the origin or structure of the whole. These rivers have cut deep clefts across the successive ranges ; they in no sense define or limit them. The precise limits of the Himalaya are unknown ; the complex system merges to the west in the mountainous country north of Afghanistan ; on the east it is lost in the unexplored 2 A NATURALIST IN HIMALAYA reo-ions of Northern Burma and the Chinese borderland. Viewed from the south the Himalaya seems to rise like a sheer wall direct from the alluvial plains of India. The snowy range is visible from a great distance. On a clear day the white outline of the peaks can be seen over a distance of 1 50 miles, and a conspicuous summit may display its white crest against the sky at more than 200 miles away. This prospect over so vast a distance is visible only on the clearest day. Otherwise the mountains are concealed from view. The atmosphere is so often permeated with a fine dust that the vision of distant objects is obscured, and the Himalaya then appears, not as a white glistening line of snow, but as a gloomy uninvit- ing mass hidden in a veil of dust and not unlike a bleak headland appearing through an ocean mist. On approaching nearer to the mountains their lines grow more firm, their summits more distinct. From the level plain we seem to gaze upon a rocky wall. We are too close beneath the mass to see the suc- cessive ranges rising in ascending slopes, and the confronting barrier of the lower hills conceals the scene of chaos that lies behind. The mountains seem to stand like a sheer precipice towering above an alluvial bed, and to limit the broad expanse of plain with an almost perpendicular wall. It is the sudden contrast between plain and mountain that is the striking feature in the landscape. Their junction more resembles the face of a great cleft than the denuded slope of a gentle fold. The contrast is abrupt. The eye moves unchallenged over the vast expanse of plain till it meets the sheer Himalayan A HIMALAYAN VALLEY 3 wall. It is like gazing from a boundless ocean on to a rocky coast. Valleys lead into this mountain barrier and penetrate the snowy range. They mark the course of the main rivers along which the drainage of the system flows. I pass to one of these valleys at the western end of the Himalaya close to where the Indus river emerges on to the plains. This is the valley that leads into the district of Hazara, a narrow tongue-shaped strip of British territory projecting northward into the ranges. I take it as a typical example of a portion of the Western Himalaya and will consider certain aspects of its natural history in some little detail. This district of Hazara is a long and slender wedge of British soil driven in between two independent territories. It extends from 33° 44' to 35° 10' N. and 72° 33' to 74° 6' E. Its total length from north to south is about 120 miles, and its width varies from 56 miles at the base to 15 miles at the termination of the wedge. This strip of land has definite boundaries. To the south its foot-hills sink into the plains of the Punjab ; to the north it rises into massive peaks 17,000 feet in height that blend with the still loftier summits of Western Kashmir. Its lateral boundaries are distinct. On the west it is limited by the Indus river and the country of the independent frontier tribes ; on the east it joins the territory of Kashmir. The upheaval of the Himalaya has involved the district of Hazara. It has raised its surface into a system of mountain ranges that course across it in parallel folds. From the north-east to the south-west these folds traverse it in successive tiers. The lower ones to the south are clothed in forest ; the higher are 4 A NATURALIST IN HIMALAYA draped in glaciers and snows. All are hewn into diverse forms and are peopled with many and varied species. It is this great upheaval that has given the wonderful variety to the landscape, that has moulded the district into mountains of every shape, carved it into valleys of every stage of growth, and has bestowed on it every degree of temperature from the oppressive warmth of the sub-tropical valley to the cold of the perpetual snow. The general features of the country are best seen from the summit of a hill seven or eight thousand feet in height. A wide expanse of landscape is then exposed to view. Far away to the north-east the mountains of Kashmir rise aloft in snowy peaks and ranges. Their ice-clad summits rise in a bare glisten- ing mass above the green wooded slopes of the nearer hills, but their distance is so great that it is impossible to appreciate their true magnificence and the stupen- dous scale on which they are built. The western boundary lies closer to us. It is dark, dreary and uninviting. Rugged black ridges of inhospitable mountain rise upward from the Indus. Pine forests cover many of its slopes ; narrow paths wind along its spurs, and on the peaks and projections of its ridges can be seen the block-houses of stone that mark the last outposts of the empire. This is the frontier. The main ridge is the barrier between British territory and the land of the independent Afghan tribes. To the south the eye sinks down on the vast plains of India. Like a sea they extend outwards from the mountains and fade into the far horizon. Hundreds of miles of imbroken plain expand and a whole country is spread out beneath the view. Everything is dwarfed MAP OF WESTERN HIMALAYA. [Face p. 4.] A HIMALAYAN VALLEY 5 to miniature. Seeming clumps of greenery are forests, villages are cities, and glistening threads are noble rivers. All are dimmed beneath a haze of shimmering heat. Further and further we trace this sea of land into the hot mists that envelop it, till, in the far horizon, sky joins plain through the quivering haze and heaven and earth seem one. Such is the distant prospect from a peak in Southern Hazara. The nearer view is a less imposing one. The sub-Himalaya that stands around is built on a less rugged scale. Peaks and ridges of eight to ten thousand feet in height rise from broad fertile valleys four to five thousand feet below. In parallel ranges they sweep across the country. The higher slopes are clothed in dense forests of conifers, but lower down the dark brown rocks support but little verdure and project in bare unsightly masses through a rank mountain grass. Terraces creep up the sides of the narrow glens or rise like giant steps up the rounded mountain spurs that stretch out into the valleys. The cultivated tracts lie far beneath nestling amongst the hills. As fertile plains they spread themselves before the eye. In the spring, when clothed in crops, these valleys are beautifully green and shine with a dazzling yellow from the brilliant fields of mustard. But in the autumn, when the harvest is saved, the green and gold expanse is replaced by a dismal brown. The parched hills then merge into the duller plains ; the forests stand out in pleasing contrast, and here and there dotted over the uninviting valleys are the ceme- teries marked by little clumps of trees, still green or fading into autumn yellow, like oases in a desert. The art of man is evident throughout the scene. Flat- 6 A NATURALIST IN HIMALAYA roofed villages, all facing southward, stand scattered through the valleys ; others for protection form a stronghold on the summit of a low hill or on the ridge of a rocky buttress extending outward from the mountain side. The tiers of fertile terraces that climb the flanks of the hills indicate the industry of the people. Not content with the alluvial plains, they have followed the narrow streams up the mountain sides and forced the cultivation into every nook and cranny on their margins. They have employed much labour in this work. The terraces are irrigated by an ingenious system of stony channels that convey the water from a mountain stream. Their isolated houses of mud nestle in sheltered (jlens or hide in forest clearings, or stand perched on mountain spurs at almost inaccessible heights. In the bed of every valley is the river, seen from the mountain summit like a winding silver thread. They glisten in their slow sinuous course as they wind throuci'h the fertile land or with almost torrential force rush over their stony beds. All are tributaries of the Indus that, far away to the west, like a narrow glistening streak, hides beneath the rugged mountains and separates this country from that of the wild tribes beyond. I made many short journeys into the surrounding mountains, climbed the hills, explored the rivers, the forest and the glens, but could never tire of standing on a wooded peak and gazing on the massive ranges to the north, contemplating the endless southerly plains or wondering at the stupendous scale on which Nature has built this rugged land and the beauty with which she has clothed it. A HIMALAYAN VALLEY 7 The main bulk of Southern Hazara is composed of Tertiary limestone elevated into hills some eight thou- sand feet in height. In bulky masses they raise their ridges high over the fertile valleys. Encircling their broad waists is a natural girdle which defines the dark forests of conifer that densely clothe their summits from the barren slopes below. It is a pleasant recrea- tion to wander from the deep valleys upward over the treeless mountain zone into these dark Himalayan forests. The murky valleys are soon forgotten as we ascend to cooler heights. We come upon the treeless zone. It is green with long mountain grass through which peep the blue bosses of the limestone. As we ascend higher we meet the forest of conifers, first a few dwarfed and scattered pines that struggle to exist a thousand feet below the forest. At six thousand feet we leave behind the treeless slopes and ascend into the gloomy woods. At the very outskirts we are greeted by birds of brilliant colour. Green parrots, shrieking as though in wild alarm, sweep high above the trees ; perched over a torrent is a verditer fly- catcher clothed in a most lovely blue, softening under different shades of light into emerald or turquoise ; and above us, flitting from pine to pine as if rejoicing in its unequalled brilliancy, is the fiery scarlet of the minivet. It is mainly the birds that beautify these forests ; their many varieties, their splendid colours, their striking contrast with the duller species of the valley, make these pine woods an ornithological paradise. We penetrate deeper into the forest under the shade of giant conifers. The woods are very peaceful. A sharp, cool air invigorates the body relaxed by the 8 A NATURALIST IN HIjMALAYA damp heat. On every side stand pines and firs of enormous bulk and stature. The blue pine and silver fir, intermingled with the spruce and deodar, clothe the hillside in a dark green. The colour is softened by a lighter vegetation mainly composed of the cherry, ilex, chestnut and sycamore. The trees drip with moisture. The sun is dimmed by their broad expanse; all life is still beneath their looming shade. Tiny flowers of every tint raise their heads above the tangled undergrowth, some of the only spots of colour in the gloomy scene. We climb higher and penetrate deeper into the forest. The gloom deepens and active life seems to be absent, but it is only lost in the immensity of the scale. The birds are scattered through the ocean of verdure and are hidden in the lofty trees. Living creatures in reality swarm in the dark forest. Peer into every mossy nook, search amongst the ferny dells, break asunder the dead, crumbling tree-trunks, and thousands of living crea- tures will be revealed to view. Troops of monkeys go crashing through the trees. Woodpeckers of brilliant plumage clamber nimbly up the giant conifers or sweep through open glades in long undulating flight. Flocks of titmice hang upon the branches, doves rise in alarm from the green undergrowth, beautiful blue magpies flutter heavily from tree to tree, the hills re-echo to the low call of the cuckoo and the sweet note of the whistling-thrush, or the nuthatch chops and hammers on the leafless top of an old gnarled pine. In every dark recess spiders have hung their pendent webs or have spread from branch to branch their inimitable snares ; beneath the stones they seek a shelter or chase their victims over the A HIMALAYAN VALLEY 9 moist ground. If numbers govern, then the spiders rule the forest. Shake the branches of the conifers and a cloud of tiny flies are awakened from their slumber and flutter out into the day. The forest teems with active life if we could but see it ; it is hidden from our view in the vast immensity of the scene. Over all there reigns at times a strange uncanny silence. No wind rustles in the dark pines, the distant twitter of a bird but seldom greets the ear ; the one sound that breaks the solitude is the low rumble of the mountain brook as a thousand feet below it leaps from rock to rock in an endless succession of torrents and cascades. When evening approaches the forest grows still more peaceful and sublime. The setting sun at times glows with a rich orange tint, and, as its dying rays steal through the leafy chinks, the foliage glistens with every shade of vernal. The silence deepens, but the rippling brooks sing louder through the trees, and as the first stars peep through the canopy of heaven the majesty of the Himalayan forests sinks into a perfect peace and solitude. Such is a very brief description of the general features of Hazara. It is a necessary introduction to the study of its life. I never had an opportunity of visiting the northern and massive extremity of this geographical wedge, but for years explored over and over again the valleys, gorges and dense forest-clad hills that trend gently to the south. For the naturalist it is in an interesting little corner of the world. Here each spring he will see the long stream of migrant birds moving northward by slow degrees from the stifling plains of the peninsula to the breeding-grounds 10 A NATURALIST IN HIMALAYA of Siberia ; and each autumn he will greet their sure return. He will sec a smaller host of local migfrants which in the cold of winter descend into the valleys and in summer ascend to the higher and cooler hills. In the glens, the fields, the gardens, the woods he will find insects numerous aijd full of interest, and many a happy hour he might spend with the living creatures of the pools and streams. Fortunate is he who can spend some years amongst the mountains of Southern Hazara and amongst the living beings whose natural history I shall endeavour to describe. CHAPTER II HARVESTING ANTS General habits — Appearance of ant — Sexual forms — Collection of seeds — Effect of heat, cold, shade, rain, darkness — Cessation of toil — Division of labour. I WILL commence my record of the natural history of this valley with an account of the habits and instincts of that common and conspicuous ant, Messor barbariis. In all places, at moderate elevations, this harvester pursues its labour. On the dusty roads, in the shady gardens, on the bare hillsides, and amidst the fields of Indian corn, long trains of ants, some empty, others laden with the spoil of harvest, move in an unceasing flow. At one spot a colony of ants establishes a formicary ; tunnels are dug into the earth and subter- ranean granaries are excavated in which to store the harvest. From the entrance to the formicary a solid track, smooth and well defined, leads out to where the harvest is collected. Should the nest be a populous one, a number of similar roads may radiate in dif- ferent directions. These roads vary in length ; the longest I have seen in these hills measured thirty yards. Following the road outwards, we find that its further extremity gradually fades away, expanding into the collecting area where the seeds of the grass or Indian corn are waitinof to be o-athered in. To and fro along the road the ants move in different direc- 11 12 A NATURALIST IN HIMALAYA tions ; those returning to the nest are laden with seeds which they carry to the hidden granaries ; those leaving the nest are hastening empty-handed to the foraging-ground in search of a fresh burden. Messor barbams is an industrious though not a very agile ant. It is a dark red insect with a smooth and polished surface. Its head is square and strong, its thorax massive, and its large abdomen oval, black and shining. The members of the same community vary greatly in size. In the same nest are seen large workers one-third of an inch in length and smaller workers only one-sixth of an inch in length, and connecting the two extremes are many intermediate forms. The largest workers, though twice the length of the smallest, yet still more exceed them in their robust build, A dense multitude must throng each nest, for the roads are often crowded with their numbers. The nests at these elevations, an altitude of 4000 feet, do not contain such large numbers of individuals as those seen in the plains of the Punjab. At higher altitudes the communities are still less populous, and in these smaller nests the common red species, Messor barbartis, tends to be replaced by a blackish form dignified by a distinct specific name, Messor hwiala- yanus. A few thousand feet higher the harvester entirely disappears. I have occasionally seen them at 6000 feet far away on the extreme frontier. And once I found an impoverished nest of M. himala- yanus on a mountain summit at 8000 feet, an altitude which, I think, must mark the extreme limits to which they ascend. This ant commences active operations early in The Harvesting Ant {Messor barbariis) X 5. The Carnivorous Ant [Myrniecocystus setipes) X 3. [Face p. 13.] HARVESTING ANTS Ife 13 March. Throughout the winter not a harvester is seen, but the first warm days of spring vivify them from their sleep and a start is made in the estabhsh- ment of a nest. A few workers, drowsy and indolent, emerge from the ground. They move slowly about waiting for the warm sun to dissipate their sloth. Soon they commence to work. Each ant emerges from the nest holding in its mandibles a little load of earth ; this it throws to one side and returns for another burden. Other workers join the original pioneers and excavation advances. In these early days the work is sluggish and intermittent owing to the changing weather ; a bright sun moves the ants to toil with energy, the rain or cloud or bitter wind drives them inert to the nest. An important duty at the commencement of the season is the clearance of the last year's galleries. The ants occupy themselves in ejecting the chaff and husks from the nest. Even in this work they display some system, not casting about the refuse haphazard, but collecting it into a heap at one special place. Slowly the tunnels are deepened, the granaries are enlarged, piles of debris accumulate about the orifice of the nest, but as yet no attempt has been made to gather in the harvest. An important event must first occur ; the sexual forms must emerge before the storage of food begins. Towards the end of the month they appear. The winged males and females creep slowly from the nest and out into the open. The workers pay them much attention, caressing them with gentle strokes of their antennae. But the prospective parents are eager to be away ; they soon climb to points of vantage on the tips of the neighbouring blades of grass and fly off 14 A NATURALIST IN HIMALAYA into the air. The sexual forms having dispersed, excavation continues and is soon completed. The ants next seek the harvest. They spread out in all directions from the formicary, searching- the ground for seeds. As soon as they discover a suitable area — it may be twenty or more yards distant from the nest — they rapidly wear away a regular thoroughfare between the collecting area and the nest, along which they pass and repass in a busy throng, either hastening to the nest laden with their little stores of provender or hurrying out to renew their burdens. From the un- ceasing tramp of millions of tiny feet a well-worn and conspicuous road is formed. There is no right of way, but there is no confusion ; all pass backward and forward with perfect regularity ; in fact the air of business, the bustle, and the all-pervading order remind one of the swarms of human beings hurrying along the highways of our great cities. The gathering of the seeds is well worth observa- tion. The ants move out along their road, reach the distant end and spread themselves over the collecting area. Some explore the ground, others ascend the plants to cut the seeds that have not yet fallen. Each ant, having secured a suitable seed, makes straight for home. Over every obstacle it pushes or drags its burden, much heavier than itself. With wonderful strength and energy it surmounts the stones and little hillocks that oppose it, or winds its way through a miniature forest of grass. It at length reaches the beaten track, hurries at a great pace along the smooth road, ignoring all its comrades in its eagerness for home. Arriving at the door, it enters, carries its load down the tunnel until it finds the granary. There it HARVESTING ANTS 15 yields its burden to other workers whose office it is to receive the seeds, strip them of their husks, and eject the useless chaff on to the neighbouring refuse heap. The ants are not very particular as to the nature of the seeds they select for storage. I have collected twenty different kinds of seeds garnered by this harvester. Nor do they always confine themselves to nutritious seeds, for on an almost barren hillside I have seen them collecting dried fragments of grass, more, I suspect, from the force of instinct compelling them to collect something rather than from any value they could derive from the grass. I have watched them storing the pith of the Indian corn which could scarcely have any nutritious value. On one occasion I observed them selecting their harvest from a heap of bird-droppings, and often they explore a pile of horse-dung, which they tear to pieces, transporting the half-digested fragments to their home. They occasionally gather insects to the nest. Termites, the legitimate prey of almost every living creature, are eagerly seized, lodged in the formicary, and the wings, like the husks and chaff of the seeds, are thrown out on the refuse heap. To most ants the Termites are a tasty morsel. MacCook has observed the agricultural ant of Texas, which also stores nutritious seeds, bearing to the nest such numbers of Termites that "the vesti- bule became choked, and a mass of struggling anthood was piled up around the gate." The conveyance of the seed is a great labour, but a still more difficult duty for the harvester is to grasp the seed in such a manner as to make it suitable for transport. The seed must be held by one extremity so that its bulk is directed forwards in front of the 16 A NATURALIST IN HIMALAYA ant's head and elevated from off the ground. It is thus often very difficult to grasp, and places the ant at a mechanical disadvantage, but in no other position is the ant able to carry it. I have watched the ants persistently struggling with the seeds in the endeavour to obtain a suitable grasp. They often display much cleverness and determination in the way they seize the seed, first at one point, then at another point, and test it in every direction before they finally reject it as an unsuitable load. Nevertheless, numbers of seeds are cast aside, not because they are unwholesome food, but because they cannot be carried. Messor, like the harvesters of Europe and America, not only picks up fallen seeds from off the ground, but ascends the plants and cuts off both ripe and unripe seeds with its mandibles. But I doubt very much if, like some ants, they ever employ so intelli- gent a division of labour as to detail certain of the community for the purpose of cutting and dropping to the ground ripe seeds, and assign to others the duty of carrying the fallen seeds away. Certainly when I placed some food in a shallow watch-glass fixed to the summit of a perpendicular stick close to the nest, the ants that climbed into the watch-glass never threw down fragments to those below, but each one carried its own little load along the difficult journey round the edge of the watch-glass, down the stick, and back to the nest ; yet in this experiment they might have expected to learn how much better a policy it would have been for them to divide their toil, as many of them, while struggling with their loads along the edge of the watch-glass, overbalanced and tumbled to the ground, and thus had a practical lesson in the HARVESTING ANTS 17 shortening of the journey and the diminution of their labour. Although not very particular as to the nature of the seed which they take into the nest, they are very careful to satisfy themselves that it is quite dry. Moist seeds are always rejected, and in rainy weather, when the seeds are unusually damp, the ants, after collecting them, spread them around the orifice of the nest and allow them to lie there until sufficiently dry. I found that the ants were very fond of fragments of walnut and carried them eagerly away, yet, if moistened with water, not a particle would be lodged in the nest until first thoroughly dried in the sun. The garnered seeds are not always ripe, but may be removed from the plant while still green. Sometimes the seeds have broad green leaf-like expansions, especially in a species of dock [Rtimex hastatus), which is a common source of harvest. And as each ant holds its little burden in the air, the green leafy seeds sway from side to side, and the returning column reminds one of the descriptions of the leaf-cutting ants of tropical America, and recalls the vision, to which Belt compares them, of a moving Birnam Wood. I have mentioned that nest-construction beo;ins in March, but this is only the case at altitudes of about 4000 feet. In the plains of the Punjab work com- mences much earlier in the year. I have there noticed the winged forms emerge in large numbers at the end of January. In all probability the species will be found active on the plains during any month of the year. Moderate sunshine is the main stimulus to labour, cold to sloth, while all industry ceases in an intense heat. On the first days after emergence work c 18 A NATURALIST IN HIMALAYA continues only in the sunshine, later, as the hot season advances and while the days are still pleasantly cool, the harvesters toil the livelong day, careless either of sunshine or shade. Still later, when the heat increases and the sun's rays beat fiercely on the earth, the ants evade the warmth that they first enjoyed and abandon all work except in the cool hours of the morning and evening. They are not such slaves to the sun as the harvesters of America, which so delight in the warmth that they refuse to construct their nests in shady places, and will either desert the nest or cut down the overhanging leaves if the latter should intercept the full light of the sun. The Messor ants do not object to a well-shaded nest ; in fact in midsummer it is an advantage to them, for the ants will then work through the heat of the day round about the nest, and continue to collect the harvest wherever there is suitable shade. They will not then extend their operations into the full sunlight until the cool of the evening. Rain greatly disturbs the even life of the formicary. It checks all industry, obliterates the roads, washes the sand and gravel down the orifice to obstruct the tunnels of the nest. In these hills the rains are frequent and intermittent, and the ants have as a consequence to perform much unproductive labour after every downpour. From within the nest they pull away the obstructing debris grain by grain and are ultimately set free. On one occasion, after an unusually heavy storm, the ants did not escape from their prison until two and a half hours after the rain had ceased. The brisk and active manner in which they ran about the opening suggested that they were highly pleased at their release. HARVESTING ANTS 19 It is interesting to observe the sudden change that takes place in the general operations when work ceases for the day. I have endeavoured to make clear that, when gathering in the harvest, all the returning ants carry in their jaws a contribution to the general fund and all the ants leaving the nest are empty-handed. But if the ants be observed shortly before sunset the normal progress will appear reversed, for thousands of ants possessing no burden will be noticed hurrying from the field of harvest along the beaten track and entering the nest. The cause of the sudden change is that work has ceased for the day. Innumerable ants have been searching diligently for seeds but have been unrewarded. Evening approaches, and by common consent they cease their labours. Though failing to secure a load, they all converge to the common track and hurry along to the nest. Here and there a more fortunate worker, dra^oino- labori- ously a large seed, is infected with their haste and, though struggling along more violently than ever, is left hopelessly behind. On they come in an ap- parently endless stream ; they pour into the nest, for work has ceased for the day, and they retire to rest for the night. The principle of the division of labour is an indication of the degree of organization attained in any com- munity. Order, system, internal and external economy largely depend on different members, each performing its own definite task. The principle is illustrated in the life of the harvester. The larcre class of worker, or soldier-worker, assumes a different part in the general management of the formicary from that taken by the host of smaller workers. They do not join in 20 A NATURALIST IN HIMALAYA the routine duties of excavation ; they rarely carry a load of debris to the refuse heap ; they quietly crawl about the opening while the smaller workers toil laboriously on. If we watch a nest during excavation, it will usually be found to have two or three soldiers stationed at the entrance. From time to time they leave their post of duty at the gate and creep about over the husks and excavated earth as though to satisfy themselves that the work is proceeding satis- factorily. Then they again return to the entrance. At first sight it appears a strange dispensation of nature that the larijest and stronoest should be the laziest in the community. But this is far from being the case. Interfere in any way with the general routine of work and none will more resent the in- trusion nor attack more ferociously than these sluggish soldiers ; place any impediment in the way of excava- tion and the soldiers will be tireless in their activity until it is removed. It is difficult to escape the impression that the soldiers stationed at the entrance maintain a general supervision over the smaller workers in their task of excavation, direct the scheme of opera- tions, dictate the methods by which new difficulties are to be overcome, and stubbornly defend the nest against all intruders. I will mention one instance displaying the energy and special duty of the soldiers in the protection of the home. I found a nest of Messor Jiimalaya7ius situated on the side of a limestone cliff with its occu- pants busy as usual storing up supplies for winter. At the time I first detected the nest no soldiers were stationed at the gate. Eighteen inches distant from the entrance to the Messor nest a complete migration HARVESTING ANTS 21 of another ant community (Acantholepis frmicjifcldi) was in progress, and thousands of the tiny workers were moving rapidly, in perfect order, to their new abode, and many of them were laden with larvae. The migration was no doubt due to the recent rains flooding the deserted nest which was situated at a lower level amongst the stones not more than ten feet away. The fact worth noting was that, though the migrant stream passed in close proximity to the Messor nest, yet the discipline of their advance was maintained with such regularity and order that no antagonism occurred between the two species. The discipline of the migrants and the industry of the harvesters con- tinued without either party causing the slightest interference or opposition. Seeing this harmony between the two species, I disturbed the stream of migrants. Immediately the whole body of ants was thrown into a state of great confusion. All was flurry and excitement ; ants rushed hither and thither and the commotion spread back along the advancing line. Discipline was lost, and the orderly progress of the insect- army was changed into an excited mob of migrants. Many rushed into the nest to seize the larvse and transport them to a place of safety, while others dashed from place to place communicating the news with their antenna; and spreading a report of the disturbance throughout the whole community. Now as soon as I disturbed the line of miorants and spread confusion amongst their ranks, the two species, which before worked harmoniously, at once came into furious contact, and many of the migrating ants in their excitement rushed right across the Messor nest which before they ha,d passed in peace. Two 22 A NATURALIST IN HIIMALAYA laree Alcssor soldiers then came to the entrance of their nest, and one took up the position of guard on cither side of the opening. Whenever a worker of the other species approached within an inch of the entrance, one of the soldiers would instantly rush forward and endeavour to seize the intruder; but although the soldiers were too heavy and clumsy to capture the agile Acantholepis, yet they succeeded in guarding their nest successfully against the host of excited migrants. None of the smaller workers at- tempted an attack, but continued to perform their domestic duties under the safe protection of the two soldiers. Thus do the soldiers of the species M. himalayanus perform distinct and specialized duties in regard to the protection of the nest. The following is another instance of the division of labour in this community. A number of the ants were excavating a nest from beneath a small stone situated against a sloping bank. The earth which they removed had accumulated into a heap, and numbers of the workers were engaged in carrying their loads from the inside of the nest on to the surface of the heap. The surface of the mound thus formed was flat, and the extremity furthest from the nest formed a miniature precipice overhanging the ground below. I observed that the ants emerging from the nest never threw their loads down the precipice, but laid them on the surface of the mound. The ants, however, had stationed a special worker on the brink of the precipice, and, as fast as the excavating workers deposited their loads on the flat summit of the mound, they were taken over by this special worker, carried by her to the edge and pitched down the precipice. This appeared to be the HARVESTING ANTS 23 particular duty of the one ant. Each worker could with very little more trouble have advanced another inch with its burden and thrown it over the precipice ; but it was apparently a better division of labour and in some way more economical for the community, that each worker should take . its load only to the summit and there deposit it, but that the size, shape, and general construction of the mound should be the peculiar duty of one particular worker. But apart from these special instances, we observe the same principle employed in the routine of daily life. The harvesting of grain and the casting out of husks are duties which are carried on simultaneously in the same nest. In this work the ants divide their labour : certain individuals harvest grrain but do not undertake the removal of husks ; others eject the husks but take no part in the storage of grain. And not only do these ants divide their toil amongst their many members, but they sometimes advance still further in the division of labour, that most valuable of all functions to any community, in that they occasion- ally reserve one aperture of the nest exclusively as an entrance for those workers carrying in the harvest, and another aperture solely as an exit for those other workers eno;ag"ed in throwing out the husks. Thus do the harvesters divide their labours in due regard to the business of their lives. The strict economy of the nest needs the untiring help of all. But each individual has its own duty ; each its own particular place in the long monotony of daily toil. CHAPTER III SENSES AND INSTINCTS OF HARVESTING ANTS Sense of smell — Sense of direction — Communication — Play and sport — Peacefulness — Mode of defence — Emotions — Economy — Migration — Pliability of instinct — Aberration of instinct— Folly of ants. The special senses of ants are well worthy of investi- gation. It is f^encrally admitted, and I am convinced it is true in the case of the Indian harvesters, that ants find their way mainly by the sense of smell. It is very easy to demonstrate the acute development of this sense by surrounding the opening of the nest with a narrow ring of powdered camphor. The ants become very excited ; they often recognize the odour fully an inch distant from the ring and dart backwards in apparent distress and alarm. With the exception of a few brave spirits that in their confusion dash across the ring, those at the mouth of the nest are cut off from the outside world, neither can those cutting and carrying the harvest enter within. Labour, however, does not cease, for the outside workers, after vainly endeavouring to brave the powerful odours of the camphor, deposit their burdens outside the ring and go off in search of more. It is the possession of this strong sense of smell that enables the harvesters to keep to the same road and pursue an unerring course ^0 and from the nest. Unusual landmarks placed 24 < W ►4 > INSTINCTS OF HARVESTING ANTS 25 beside their road do not in the slightest confuse them, but if the finger be drawn gently across the track they instantly recognize the interference, appear to have lost their way, and not until a number have crossed and recrossed is the orderly progress again resumed. I placed a strip of cardboard an inch in width across the track of the harvesters. This caused intense commotion, and not until many hours had elapsed did the ants carry their loads over the narrow cardboard strip. When the stream was restored I then removed the strip and the ants were just as much confused as before, although I had given them back their original road. They were unable to recognize their old track, since the odour had disappeared while covered with the cardboard. I transferred the strip over which the ants were freely moving to another track and placed it down in a manner similar to the first, but the ants were not now in the slightest confused ; they carried their burdens without any hesitation directly across the cardboard strip. In this last little experiment the strip of cardboard had been given the natural scent by the numbers of harvesters that had run across it on the first track, and it thus became indistinguishable from the usual road to the ants which hastened alonof the second track. In the employment of camphor to test the sense of smell we stimulate the pugnacity of the soldiers. Camphor is a substance which the harvesters dread ; from its powerful odour they dash headlong away ; nevertheless, so plucky are the soldiers, that I have seen one grasp a large fragment of this stupefying substance in its jaws and endeavour to drag it away from the nest. When a harvester leaves the general track in search 26 A NATURALIST IN HIMALAYA of seeds it is, I think, by the sense of smell that it finds its way back again to its track. To test this I placed near the nest away from the track a perpen- dicular stick with a little platform on the summit on which were laid some chopped walnuts. I transferred a few ants to the platform, and after a little time they continued to come backwards and forwards between the platform and the nest, on all occasions making a straight course from the foot of the stick to the opening of the nest. While an ant was selecting a suitable morsel on the platform I moved the stick one inch to the right. The ant descended the stick with its load, but when it reached the ground, instead of making direct for the nest it wandered aimlessly about, carried its load further and further away until finally I lost it in the grass. It could not have been a special sense of direction that guided the ant from the foot of the stick to the nest, for the movement of the stick one inch did not appreciably alter its relationship and direction in respect to the nest, yet the ant was hope- lessly lost. I believe the ant, when away from the common road, on its return journey follows the line of its own scent, and when it deviates from that line it is lost. And if this be true, then the sense of smell must be developed to an inconceivable degree. It is in itself surprising to watch the thousands of ants moving along the common track, each guided by a powerful sense of smell ; but it is far more wonderful to see a single ant, away from the beaten road, scenting back along its own track and unerringly working over the same line that it previously followed, though that line may have been crossed and recrossed in the interval by hundreds of other ants. A harvester must, there- INSTINCTS OF HARVESTING ANTS 27 fore, be capable of detecting its own scent from that of every other individual in the nest, and it follows that every single ant in a community must have a different scent. Marvellous as is the sense of smell, it is impossible to consider it as the sole o-uide in the activities of the harvesters. During certain operations they seem to be impelled to take the right course by some mys- terious sense of direction quite incomprehensible to us. This is well illustrated by the manner in which the ants find their way home when engaged in funereal duties. Certain ants bury their dead, and are even said to follow the corpse with reverence to the grave. The harvesters do not inter their dead beneath the soil nor do they indulge in any funereal ceremonies, but are nevertheless very careful in disposing of the dead bodies of their companions. When a dead ant belonging to the community is discovered, one of the workers takes it in its mandibles and carries it far away from the entrance to the nest. The dead are taken sometimes to a very great distance ; on one occasion the ant conveyed the corpse sixty feet from the nest before it had discovered a suitable cemetery. The place chosen for the disposal of the dead is far away from the area of activity of the ants, never in the direction of the harvesting operations. When watchino- these funereal duties nothino- is more strikingr than the wonderful manner in which the ants are able to maintain the true direction over unknown ground. I killed twenty of the members of one community. Two cemeteries were selected for the disposal of their bodies, one due west and the other due east of the nest. I observed an ant which carried its dead com- 28 A NATURALIST IN HIMALAYA panion sixty feet from the entrance to the formicary. After taking up the body, it struck off in a westerly direction ; the other members of the community never moved west, as the harvest was being transported along a line running due south. Nevertheless, this ant maintained a true westerly course. All kinds of obstacles confronted it : large stones forced it to dellect either to the right or to the left ; it had frequently to rest its burden on the ground and seize it in some more favourable manner in order to raise it over an obstruction ; sometimes it was forced to carry the body up the stems of plants or to make wide deviations to avoid some difficulty; at other times it had to cease its endeavours to carry the corpse and was compelled to turn about and drag it irreverently over the ground. As the ant moved away sixty feet distant on the unfrequented side of the nest, it must have been travelling over unknown ground ; all landmarks must have been strange ; every obstacle forced the ant to turn in various directions, yet it always returned to a true westerly course. Other ants followed with more corpses though not on the direct track of the pre- ceding ant, yet the course was always a true one ; it never deviated from a due west. I am unable to understand how an ant can maintain a true course over unknown ground unless it possesses some peculiar directive sense beyond our limited comprehension. I expected that the ant, after the disposal of the corpse, would return back along its own track, using its powers of scent, or possibly the landmarks on the route, as a guide to its return journey. I carefully marked the outward track, but, though the ant made a straight course for home, it did not retrace its actual INSTINCTS OF HARVESTING ANTS 29 footsteps. It travelled from a foot to two feet distant from its outward path, and consequently I do not think the sense of smell could have been its guide. I placed barriers between the returning ant and its outward track so as to conceal any landmarks, and I introduced stones and sticks as new landmarks along the line of its return, but they did not in the least confuse the ant. In front of one ant I placed a forceps, a razor, a sheet of paper, a book, and a mirror. The ant could never have seen such unusual landmarks along any track, and if it made use of landmarks as a means of recognizing its return journey, then such strange obstacles as these must have convinced it that it was on the wron2f track. But the ant was not confused ; it worked its way round the obstructions and kept straight on. Nothing interrupted its home- ward course ; nothing seemed to be its guide. It was difficult to escape the conclusion that a powerful sense of direction was the strange impulse that led it to its home. Drawing the finger over the ground in front of the returning ant did not excite it in the slightest, though, if the same be done across the main track leading from the nest, a great confusion ensues, and only after much hesitation will the ants pass over. This wonderful faculty by which the harvesters engaged in funereal duties find their way home, and which we must call a sense of direction, is, like other instincts, capable of confusion. An ant had carried the dead body of a companion nineteen feet distant from the nest and was on the return journey. I took up the ant and transferred it back to a point six inches behind on its own track. After a pause the ant took a few hesitatin"- turns and then made straio^ht for the 30 A NATURALIST IN HIMALAYA nest. After the .'int had progressed a little further, I again took it up and brought it back six inches. This time the ant was more confused and wandered about for a longer time before it found itself able to strike a direct course. After it had discovered the true direction and was travellinor in confidence towards home, I again brought it back six inches. This time, though much nearer the nest, its confusion was still greater ; it repeatedly crossed and recrossed over its own track, wandered about in all directions, and, even after it appeared to have formed a hazy idea of the position of its nest, it continued to deviate widely from its course and often wandered some distance backward. For the fourth time, and when only two feet from the nest, I brought it back six inches. Its confusion was now intense ; it seemed hopelessly lost ; it hurried hither and thither, passed and repassed the entrance of its nest, and only after a long and laborious search did it happen by chance to fall upon its home. I have not the faintest conception of how this sense of direction works. It is certainly not in the power of the ants to command it at all times. I took an ant from the opening of its nest, placed it in a dark tube, removed the tube to a point ten inches distant and then released the ant. The little creature was com- pletely lost ; it wandered aimlessly about in every direction ; not a square inch of ground on either side but it vainly explored again and again until at length it came fortuitously on its nest. Other specimens removed to a similar distance wandered as far as fifteen feet away from the nest, and others found themselves so hopelessly astray that they gave up the search and hid themselves beneath the stones. INSTINCTS OF HARVESTING ANTS 31 What can we say of an instinct such as this, at one time so sure a guide, at another time so utterly at fault ? I withdraw the ant returning from its cemetery six inches on its track and it soon regains its road ; I transfer it the same distance from its nest and it wanders aimlessly as in a dream. In one case the sense is certain, in the other it is lost. But why, I know not. The sense of smell though wonderful is comprehensible ; the sense of direction is an inexplicable mystery. That many ants are able to communicate intelligence one to the other is an undoubted fact. I shall later illustrate the high degree to which this faculty has been developed in another species found in the valley. The harvesters, however, can claim the power ot communication only in a moderate extent. The one kind of information, and that a most important one, which these ants can undoubtedly communicate to each other is the presence of danger. When one ant in the society is alarmed, the news spreads amongst all the members with extraordinary rapidity. On one occasion, when the ants had collected into little groups of ten to twenty individuals and were sheltering from the rain in a dull torpid state, I touched a solitary ant that was resting quite separate from any of the groups. The ant hurried away in alarm to the nearest group. As soon as it touched one of the ants in the group with its antennae, the information was rapidly spread from individual to individual and the whole group broke up in wild alarm. As each excited ant reached another group the same flurry ensued, and in a very short space of time all the torpid groups were dashing about in disorderly commotion. Thus a single ant 32 A NATURALIST IN HIMALAYA had imparted to the whole nest a sense of impending danger. It is surprising that these ants do not appear to have the power of informing one another of the discovery of food. With most of their lives employed in collect- ing seeds, it might have been expected that their faculty of communication would have been developed to this degree. But such is not the case. I placed some chopped walnuts, of which the ants are very fond, a little distance from the nest. I marked the first ant that discovered the nuts with a speck of white paint. After carrying off a morsel it returned again and again, but never brought any companions. All the ants marked in this way possessed a very excellent memory for location, but they were utterly unable to bring others to the place. If an ant is lost it can gain nothing by questioning another ant. I have frequently watched an ant seeking in vain for the orifice of its nest, meeting with other ants and rubbing antennae with them. No doubt in this way it recognized its comrades, but it found no help in regaining its road. It was clear that to ask the question " Which is the way to my nest ? " is a mode of communication far too refined for so humble a creature. However close may be the intercourse that takes place between the lost ant and its companions, the former never receives any information that may help it to find the way to its nest. I will mention some special habits which I have observed from time to time in the daily life of this harvester. The illustrious Huber remarked that ants of the species Formica pratensis play games, indulge in sport and enjoy themselves on the surface of their INSTINCTS OF HARVESTING ANTS 33 nest. The harvesters occasionally indulge in a similar pastime. One fine evening, about an hour before dusk, I noticed a group of harvesters assembled around the aperture of their nest, and playing about in so leisurely a manner that one might believe they were indulging in a general recreation after the day's hard work, and were enjoying the cool of the evening before retiring to rest. The ants were creeping about in a lazy, quiet manner. Some were rubbing one another with their antennae as though they were giving a display of their affection. Others were cleaning themselves after the toil of the day and paid special attention to their antennae, which they continually stroked with their legs. Others were more active and engaged in play or mimic warfare. Workers would snap at one another as if in friendly battle. Sometimes one ant would seize the other ; a playful struggle would ensue ; then a third ant would join in the contest and all would tumble over and over like little children rolling about in fun. The ants would then cease their friendly wrestle and run off to find another opponent and have another tumble. Like little puppies they seemed to enjoy snapping at one another and then springing away before the offended ant could retaliate with a mock display of anger. But there was no bad feeling, no true quarrel. The group was engaged in what appeared to be playful rivalry, and every ant seemed to be enjoying an idle recreation. The harvester is of an unwarlike disposition. In all likelihood if a community were to use all its organized force, its rigid discipline, its undivided efforts in an attack on other species, but few could withstand its onslaught. Fortunately for insect life it is not a D 34 A NATURALIST IN HI^IALAYA warrior but a peaceful husbandiiian. An attack on the enemy is so foreign to its nature that it scarcely under- stands the mode of battle. When in danger it trusts not in attack but in defence. It protects its nest by raising up ramparts rather than by advancing to engage the enemy. I placed a wounded specimen of the ant Caniponotus coinpressus close to the mouth of a Messor nest situated on a gravelly path. The ants seemed surprised and terrified at its presence ; some dashed about in evident alarm ; others glared ferociously with open jaws at the intruder ; occasionally a more daring spirit would seize the enemy by a leg or antenna, but would instantly flee on the slightest resistance of the stranger. The curious fact was that, with all their wonderful discipline and organization, the whole nest appeared unable to make a concerted attack on a single wounded Carn- ponotus ant which had invaded their territory, yet half a dozen of them acting together could have immediately removed it. Though unable to attack in any force, they were well aware that their nest was in danger. Workers hurried round the mouth of the nest, seized flat pebbles many times their own weight and carried them back to the entrance. Each worker placed its stone over the orifice of the nest, and in an incredibly short space of time the interior was secured by a strong barricade. The workers continued to strengthen their fortifications until the opening was completely blocked with stones, and the nest was then not only fortified, but the opening was so concealed that it appeared quite uniform with the surrounding ground. By these tactics many of the ants cut oft their own retreat, yet they succeeded in the more INSTINCTS OF HARVESTING ANTS 35 important object of shieldino- their stores and offspring from attack. It is clear that the harvesters in their struggle with the enemy rely solely on defensive action. That ants possess tender emotions is a matter of much doubt. I feel it difficult to credit them with any real feelinos of kindness or affection. But on certain occasions they do behave as if they showed a sense of sympathy towards their fellows. I flooded a nest of Messor barbariis by pouring about a pint of water down the entrance. The workers outside immediately ceased their harvesting duties and commenced to force their way into the flooded nest. It was almost pathetic to observe the careful manner in which they carried out their half-drowned companions. One could scarcely resist the idea that some feeling akin to compassion or sympathy must have influenced the ants when each was seen carrying an insensible companion from the inundated home and laying it carefully in the sun outside the nest, where it rapidly recovered and took a place itself amongst the rescuers. It is difficult not to explain the behaviour of these insects except in terms of human feeling, but in this we should be very cautious or we may greatly err. The ants are economical in the use of material and are provident in seeing that little goes waste. Even the ejected husks and chaff are sometimes of further use, as the ants will stuff them into the mouth of the nest and thus block the opening when danger threatens. They are very careful that none of the collected grain is lost. Sometimes, when the nest is situated on the face of a vertical bank, the harvesters have considerable difficulty in dragging their loads through the aperture, 36 A NATURALIST IN IIIMAIAYA aiul in their various struggles and manipulations to effect this, the seed sometimes slips from their grasp and falls down on to the refuse heap. But the prudent harvesters are prepared for such accidents and the seed is not lost. A number of workers will be seen scrambling about on the refuse heap, seeking for any seeds that may happen to fall, rescuing them from the useless husks and conveying them back to the nest. Migration of ants from an overstocked formicary is, I have little doubt, an important factor in effecting the spread of many species. It is very usual to witness certain species of ants transporting their larvae in a long migratory stream to form a new colony in some suitable crevice. But it is rare to see a migration of harvesters ; they do not appear often to increase their geographical distribution by such simple means. However, I once did observe what seemed to be a modified migration, for it could scarcely be considered a removal from an old to quite a new nest, but rather a transference from an overstocked part to a less congested area of the same nest. The ants had collected in a swarm about the apertures ; energetic workers carried the larvse from out of one opening and hurried down another ; the excavators continued their toil of digging, but the vast majority of the ants had joined together in a dense and idle throng. I never saw such a concourse of harvesters or such a display of idleness in ant life. The few engaged in transporting the larvai laboured with enthusiasm, but the remainder were wrapped in sloth. The ground around, and as far as I could see into the tunnels of the nest, was a seething mass of crawling, lazy workers. INSTINCTS OF HARVESTING ANTS 37 The monotonous course of a harvester's Hfe is to travel empty from the nest to the ant-field, select a seed and return laden to the nest. I will later show in the case of the geometrical spiders and certain insects that when an instinctive routine has been established, the creatures are in such bondage to that routine that, in face of all obstacles, the course of instinct must be fulfilled. Now the harvester, unlike some other species, is not an absolute slave to its routine. It can break the daily round of action in order to suit altered conditions. For if the seed be taken from a harvester on its return journey to the nest, the ant, after vainly searching for its lost property, will not behave like certain other insects would, and pursue its fruitless journey empty-handed to the nest, but will break its routine, turn about, and return for another load. Also, if when travelling empty to the field of harvest, it discovers a seed on the main track, it is not impelled by instinctive routine to continue its journey to the field, but will pick up the seed, face about, and hurry off to the nest. Nevertheless, I observed one foolish harvester, whose instinct seemed a more powerful guiding force than its intelligence, instead of turning back towards the nest after picking up the seed from off the track, struggle on in its instinctive routine and continue to carry the seed towards the harvesting ground further and further away from the nest. The refusal to submit to unswerving instinct is made manifest in this way. Block the entrance to the formicary and note the behaviour of the laden ants when they arrive at the closed door. They immedi- ately put things right. As soon as they arrive at the 38 A NATURALIST IN HIMALAYA nest, tlicy lay down their burdens, drag away the obstruction, and when the opening is cleared, again take u[) their loads and continue their journey. Instinct, even of the sternest kind, may often err. It is not unusual to witness harvesters storing useless materials in their nest. And I think they sometimes do this against the better judgment of other workers. For on one occasion I saw a harvester dragging along a stone, and though it was forcibly compelled by another worker to drop its useless burden, yet it again returned to the stone and persisted in lodging it safely in the nest. Instinct may lead them astray, if some of their own community are injured and then placed near the opening of the nest. I have often made this experi- ment, and observed with astonishment the signs of hostility and resentment that the ants show to their injured comrades. They look on their wounded sisters not as companions in distress, but rather as enemies. They rush on them with every sign of anger. This seems a curious case of aberration of instinct. The ants instinctively recognize that the presence of an injured companion must necessarily imply the proximity of some enemy to cause the injury, and, when they are unable to detect the enemy, they vent their hostile feeling on their dead and wounded comrades. Even after some of their number have taken on themselves the duties of burial, others will sometimes follow the body a short distance to the grave, not for the purpose of paying their last respects to a dead comrade, but, by continually snapping at the corpse, to mark their hatred and resentment at what they falsely believe to be an enemy. INSTINCTS OF HARVESTING ANTS 39 In such ways do the harvesters err, yet they share their errors with every other insect. I give them credit for a greater degree of discrimination than is possessed by certain other ants. I know of one carnivorous species which if given pebbles moistened with the juice of insects, will foolishly carry off the pebbles and store them as provender in the nest. The harvester can make a nicer distinction than this. I mingled with chopped walnuts some pieces of blotting-paper soaked in the walnut juice, in the hope of deceivinor the husbandmen as I did the carnivorous ants. But there was no cheating the harvesters. They eagerly sucked up the juice from the blotting- paper, but made no attempt to store the worthless fragments in their nest. It is very usual to hear from one who has not paid special attention to the habits of these ants an ex- pression of surprise at their extraordinary cleverness. And there is no doubt that when one first observes their wonderful organization, their law and order, their indefatigable industry, the skilful methods by which they overcome all obstacles, and to see in every act the subservience of the will of the individual to the general good of the whole community, one is tempted to exclaim " they are amongst the most intelligent of living beings." But as observations increase, it becomes more and more evident that such a conclusion would be hopelessly at fault, and that behind all this wonderful social organization there lies but the faintest glimmer of an individual intelligence. I will give a few observations illustrating the poverty of their intelligence. On one occasion I discovered a nest situated just above a large smooth 40 A NATURALIST IN HIMALAYA slcib of slate lying at an angle of about forty-five degrees. The ants, in order to pass from the ant- ficld to the nest, had to climb up this slippery slate. The journey was a very difficult one, and an ant scarcely ever succeeded in climbing up the slate without falling down many times and having to recommence the journey again and again. Numbers of ants in this way got lost ; many others were unable to reach the nest by nightfall, and probably hid them- selves away beneath the stones. The nest rapidly dwindled as it lost its workers, but the remaining ants still persisted in their struggle up the slippery slate. By travelling round the edge of the slate, a not very much longer journey, the ants could have gathered their harvest in safety, or they might have migrated to a more suitable nest. But these expedients never seemed to strike the ants ; they persevered in their impossible task until all were destroyed. On another evening, while exploring a little ravine, I observed a more obvious instance of their lack of intelligence. Harvesters, I have already mentioned, carry the chaff and husks of their seeds out of the nest, and these they carefully pile up into a little refuse heap some eight or ten inches clear of the nest. Now I found a nest-opening on the face of a vertical wall of clay bordering the side of the ravine. The ants were carrying their loads up the perpendicular wall. The nest interested me and I stayed to watch the work, as it was evident that to transport the seeds up to a nest in such a position must entail much more labour than if the nest was situated on the level around. How- ever, when I noticed the pile of chaff and husks lying on the floor of the ravine below the mouth of the INSTINCTS OF HARVESTING ANTS 41 nest, I thought that, after all, the ants stood to gain as much as they lost, for instead of having to make a journey with the refuse chaff to some little distance from the nest, they need only come to the mouth of the nest and from there drop their burdens to the ground. But as I watched, to my surprise I saw an ant emerge from the nest with a fragment of chaff, but, instead of dropping it to the ground, the foolish insect actually climbed for nine inches down the vertical wall, and then lowering its burden against the clay, let it fall down into the ravine. All the other ants engaged in the work of removing refuse con- scientiously followed its example. It is an excellent instinct that compels these creatures to carry the fragments of refuse a short distance clear of the nest, but such was their lack of intelligence that, when the nest was situated on the face of a perpendicular wall, they were quite unable to modify that habit though it involved them in much unnecessary labour. Yet in a similarly situated nest further up the ravine their folly became almost ludicrous, for here, not only did they make no use of the position of the nest for dropping refuse to the ground, but they actually carried the fragments vertically up the wall until they reached a horizontal ledge almost a foot above them, and there they carefully deposited each fragment of chaff, which was almost immediately blown away by the wind. I cannot attribute to creatures that so wastefully expend their energy in the performance of such foolish acts as these anything more than the faintest spark of intelligence. Other ants behave with equal folly when their nest is similarly situated. I have observed litde ants of the 42 A NATURALIST IN HIMALAYA genus Tctj-amormm, when excavating their nest, carry the loads of earth and fragments of stone down a vertical slab of rock and drop them just as though they were removing the particles to the mound of ejected earth usually situated a short distance from the nest. Had they dropped their loads at the mouth of the nest they would have saved themselves a con- siderable amount of misspent energy. I suspect that ants have no conception of the different dimensions of space, and that to transport seeds or debris up the vertical or alonof the horizontal makes to them no sensible difference, and that when the ant carries its little load of earth down the perpendicular rock to the correct distance from its nest and allows it to fall from its jaws, it believes, if it is capable of forming any mental impression at all on the matter, that it is building up the usual pile of debris in the neigh- bourhood of its nest, and is quite oblivous to the fact that every load it so carefully lays in the correct place falls downward to the ground. Men may wonder at the cleverness of ants, but how often do we find that their acts are the acts of folly ? Such are the activities of the harvesters in their daily life of toil. Guided by a wonderful instinct, they incessantly come and go in strict obedience to the duty of the hour. They display some of the best qualities of a race ; a perseverance in industry, an economy in provision, a resolution in defence. They have evolved an organization for the benefit of all in which each submits to the common good. They live in a world of socialism, but know nothing of its laws. Unconscious of their actions, knowing not why they toil, sufficient for the day they labour, for they INSTINCTS OF HARVESTING ANTS 43 remember no past, take thought for no morrow ; yet are they not happier — if they can feel happiness — tlian the richest of human beings ? For what belongs to one belongs to all. None is rich, none is poor ; all enjoy an equal share, none can despise its neighbour's poverty, none envy its neighbour's wealth. Nor, since they all toil in a common field, is there that jealous com- petition in different spheres which amongst humanity divides class from class to set up barriers of envy and discontent. Having no forethought they feel no cares, having no ambitions they experience no regrets. Their life is one of industry, their lot of endless toil. They strive to earn a livelihood in which each will gain its just share, but oblivious to all those stings and sorrows which darken the mind of man as he looks forward or backward on the troubled road of life. CHAPTER IV CARNIVOROUS ANTS Afynnccfliyslus seiifics—dcn^xA habits — Division of labour — Food — Sense of smell— Attitude of abdomen — Absence of sympathy- Mode of founding new colony — Intelligence — Folly. I PASS from the habits of the Himalayan harvesters to consider some other species of ants that occur less frequently in this valley. On the Indian borderland, at the foot of a gloomy mass known as the Black Mountain, stands a small stone fort, loopholed and barricaded, as a protection against the border tribes. All round are towering mountains ; those in the distance are clothed in glisten- ing snow ; those near at hand are less rugged and are softened with a covering of pines. A broad valley is enclosed by these encircling hills. It is a green and fertile tract studded with small hamlets and watered with sinuous streams. Just outside the fort, under the shadow of the Black Mountain, were some nests of that active little ant, Myrmecocystus setipes. I never saw this species in any other part of Hazara, though it is extremely common in the plains of the Punjab. How strange that I should find it again far away on the extreme frontier! It is such a very different creature from the harvesters that I will give a short description of its habits and endeavour to contrast the two species. 44 - '!» y^:.\ 4^1*? \ < < s < H 2 D O S CARNIVOROUS ANTS 45 Myr7necocystus setipes is a sturdy active species much larger and more ferocious than the harvesters. It is dark red in colour, sparsely clothed in a few scattered hairs. Its head is large and strong, furnished with powerful jaws that are armed with curved pointed teeth suited to its predaceous nature. A narrow neck divides the head from an elongated thorax which supports the six dark slender legs and ends behind in a black conspicuous abdomen. A distinct difference in size exists amongst the workers of a single nest. The larger individuals generally reach about half an inch in length, while the smaller ones scarcely exceed three-eighths of an inch ; and all gradations in size are found between the two extremes (see Plate, p. 13). It is a predaceous ant, existing chiefly on other insects, while the harvesters are peaceful husbandmen. The harvesters move slowly, regularly and methodic- ally along definite roads, but this carnivorous ant is extraordinarily active, and runs about in every direction with darting agile motions well suited to its predaceous habits. The smallest workers are exceptionally active, and take great pains to keep the entrance to the nest smooth and clean by con- tinually digging in the earth with their front legs, shovelling up the larger granules and carrying them away in their mandibles. A community of harvesters contains thousands of individuals, but the number in the nest of Myrme- cocystus probably does not exceed more than about thirty or forty members. Though possessing fewer workers than the harvesters, the excavation of the nest is by no means a slow process. The ants, by 46 A NATURALIST IN HIMALAYA their activity, compensate for their lack of numbers. To see them hurryino- from their nest with a load of earth, dashing- away to the refuse heap and darting back again with incredible speed, was to think that in their work of excavation they were engaged in a con- test against time. One of these ants, which I marked, carried out from the interior of the nest no less than ten loads of earlh in six minutes, and I do not think a harvester could undertake anything approaching such rapid work as th^it. Moreover, in their habits they score over the harvesters, for they not only carry the particles from the nest, but also possess a most valuable habit of kicking back the loose earth from the mouth of the nest in the same way as a dog kicks back the earth when rooting at a burrow. They are diggers as well as carriers, and by the former process they gain a great advantage, for, in each individual journey from the nest, the ant can confine its efforts to a large particle, and all the smaller fragments, which to the harvester would necessitate innumerable journeys, can be swept backward with its feet. A harvester, when it casts its load of earth upon the refuse heap, has no further interest but to return for another load. The carnivorous ant, on the other hand, is more attentive to the vicinity of its nest ; it often spends a little time amongst the refuse, dragging the larger fragments further away and kicking back little clouds of dust as though it was trying to make things neat and tidy, and above all to prevent the earth from fallinsf back agrain into the nest. In this act they often display a division of labour. They detail three or four of their members whose sole duty it is to pick away the larger pebbles, sweep back the CARNIVOROUS ANTS 47 refuse and clear all earth from the aperture of the nest. Division of labour was a character which I was always delighted to discover in ant life, for the specialization of work and the allotment of different tasks to the individuals of any community is one of the surest manifestations of its mentality and advance- ment. Just as specialization of function indicates the superiority of the individual being, so does the division of labour determine the progress of the race. In this connection I will give another instance to illustrate this great principle. At sunset a worker might some- times be observed paying very special attention to the outside of the nest. The other ants have retired to rest, and this ant is clearly engaged in some special individual work. It has been detailed for the par- ticular duty of sealing up the entrance for the night. One evening 1 watched the little labourer at work. It carried the larger pebbles from the refuse heap and dropped them down the opening of the nest. It dusted back the finer earth with its hind legs so as to fill the crevices between the pebbles and firmly bar the door. How strange it is that the all-important instinct of carrying out the pebbles and sweeping away the debris from the nest should here seem to be reversed, and that the ant should labour to replace the same little stones and the same fragments of earth which, earlier in the day, it had so eagerly cast forth ! Having barred the door, with the exception of a narrow slit sufficiently wide to permit of its own return into the nest, the ant entered and, with particles of earth carried from the interior of the formicary, it 48 A NATURALIST IN HIMALAYA sealed the crevice through which it had passed and then rejoined its comrades for the night. Without assistance or interference the soHtary worker per- formed this important duty ; the division of labour in the community had reached such a degree of advancement that the specialized toil of one member was to the advantage of the whole nest. In this instinct, like all others, are occasional mis- takes and imperfections. I was surprised at one foolish error made by a busy worker when engaged in the evening duty of sealing the entrance. It carefully stuffed its load, transported with much labour, into a blind hole in the ground, presumably under the impression that it was barring the aperture of its nest. But the labour of closing the formicary was not a changeless routine as are many instincts in many species. For on a subsequent evening I observed the ants adopting a somewhat different mode of work. Not only one, but a number of workers took part ; and instead of dropping the larger pebbles from out- side down the mouth of the nest, they performed all their work within the orifice and closed the opening by piling up fragments of earth all of which they carried from the interior of the nest. As the harvesters cast out the husks of the seeds, so do these carnivorous ants cast out the shells of the insects. At one nest I watched them dragging out shell after shell and piling them up at the distant margin of the excavated earth, and I thought at first that they were wonderful sanitarians for so choosing the furthest limits of their refuse heap for the de- position of their objectionable burdens. But this CARNIVOROUS ANTS 49 was certainly untrue, and there could have been no design or choice about their actions, for when I blocked the aperture of their nest with insect shells, the ants dealt with them in the same way as they would treat an obstacle of earth, and deposited the fragments, not on the shelly heap, but just outside the mouth of the nest. I have no doubt that it is a valuable habit for the ants to collect the remains of their carnivorous food all in the same place some distance from the formicary, and to pitch the earth just outside the gate. But it is all unconscious. It illustrates how strange is instinct in its thoughtless action. The ants find the nest blocked with the shells of insects, an unusual discovery. They clear away the obstruction, but they are unable to place the shells on the refuse heap for shells. All their experience tells them that the only material that blocks the gate is earth, and therefore the shells must be treated as such and thrown out on to the earth heap. Grasshoppers are the chief prey of this ant. But bees, beetles, larvae of all kinds, terrestrial shells, ants of other species, particles of dung, even their own dead comrades are carried into the nest. Unlike many other carnivorous ants, they do not combine in vast numbers to overwhelm their prey. They are not, like the harvesters, of a tranquil and peace-loving temperament, but are strong, ferocious and determined ants, and are capable of overwhelming so many insects, each by its own individual efforts, that com- bination is not very essential to the capture of their prey. Harvesters, like civilized human beings, remove £ 50 A NATURALIST IN HIMALAYA their dead far away from their homes. These car- nivorous ants, on the other liand, arc degraded cannibals, for they drag their dead back into the nest and store them up as food. UnHke the harvesters, these carnivorous ants have an indifferent sense of smell. Nothing fills a community of harvesters w^ith a greater feeling of an<'er or throws it into such violent confusion as a few particles of camphor scattered near the nest. But these ants are quite unaffected by the camphor. After recoverinpf from their slight alarm at the sioht of the strange substance, they continue their work of excavation ; they make no attempt to remove the camphor ; they will even carry into their nests insects soaked in a solution of the substance, and while every harvester will spring backwards when it has arrived within half an inch of a fragment, a carnivorous ant of this species will cross and recross a mound of camphor and apparently derive no more sensation from it than if it were the hillock of earth that was being built up outside the nest. The difference in the sense of smell in the two species is readily shown by drawing the finger across the path of a returning ant between the insect and the nest. On reaching the line made by the finger the harvester is confused and lost, but the other, unaware of any interference, continues on its path. This ant gains by acuteness of vision what it loses by the poverty of its sense of smell. By sight it recognizes the approach of a stranger and darts im- mediately into its nest. Within the shelter of the fissured aperture it peers outward with quivering antennae, watching keenly every movement, and ready CARNIVOROUS ANTS 51 to spring backwards at the slightest danger. I mention these details in my contrast of Mymnecocystus with the harvesters to indicate how greatly do the habits, instincts and special senses vary in the different species of ants. The most obvious feature in the appearance of this species is the peculiar manner in which it erects its abdomen when running about. The whole abdomen is extremely mobile, and the slender pedicle, that connects it with the insect's thorax, allows it to move with such extreme freedom as to be either extended horizontally behind or erected vertically in the air at right angles to the remainder of the body. The latter position is the most usual, and gives the ant a terrifying appearance as though it were a dangerous insect armed with a powerful and venomous sting. The ant is really a harmless creature, and I first thought that this attitude was assumed for the purpose of striking terror into its enemies and giving them a false impression of its innocent nature. But this ant has very few enemies, so I suspect that this strange attitude of the abdomen has not a defensive function but is really a balancing agent ; for when the ant is struggling with a heavy burden and attempting to drag it over all kinds of obstacles, it is a great advantage to the insect to have a large abdomen projecting out behind as a counterbalance to the weight, and the ant will naturally turn the abdomen up over the thorax when the jaws are empty and the counterbalance not required. I had read of certain ants treating one another with affection, and I have mentioned an instance of the harvesters rescuing their companions when in diffi- O'Z A NATURALIST IN HIMALAYA cullies, so I ih(^uoht that these rapacious workers mi^ht, i)erha[)s, behind their cruel nature, possess a little spark of kindness. 1 imprisoned one of them by fixing its large abdomen firmly in the earth and allowed the head and thorax to project above the surface. But its fellow-ants showed no compassion, no desire to rescue, not a spark of pity. They attacked their imprisoned comrade as though it was their greatest enemy. One endeavoured to bite off its antenna;, another to tear away its legs, a third seized its narrow neck and used every effort to decapitate it. All struggled with the prisoner to drag it unmercifully from the pit. Nor did the imprisoned ant see any sympathy in this rough treat- ment, for it attacked every worker that approached, opened wide its jaws, closed with its comrade as with a foe and batded for its life. At length, having failed by force to drag it from its prison, the workers com- menced to dig. As they did not dig very intelligendy or show any co-operation in their actions, it took them a long time to uproot their companion, now wounded in the struggle. At length, having unearthed it, they certainly bestowed on it no sympathy, but dragged the unfortunate creature for provender into the nest. Some ants may, perhaps, be imbued with a sense of pity, but there is no compassion in these cannibals. It has frequendy been observed that ants possess the peculiar habit of carrying their companions about in their jaws, but it has seldom been possible to detect any purpose in this strange action. I have noticed ants of many different species transferring their comrades from place to place, but they always seemed to lay them down and release them haphazard without CARNIVOROUS ANTS 53 gaining any special object. However, one day in a nest of this species which I had under close observa- tion, I did detect a reason for these strange efforts. I noticed that at short intervals one or two workers emerged from the nest each carrying a companion in its jaws. They seemed to behave with more purpose than usual. Each emerged hurriedly ; each made off in the same direction ; each acted with enthusiasm as though it had an object in view. I followed one of these ants and found that it conveyed its companion to another nest of the same species seventy-two feet distant. The other ants were encrac^ed in the same task. A continual transfer of workers was in progress from nest to nest, and the transferred ants were always carried by their companions. The supported ant lay passive and resistless. It hung back downwards beneath its supporter, with its slender legs entwined round the body and jaws clutching tightly the jaws of its companion. I have some doubts as to why this transfer of ants should take place from nest to nest and why so strange a mode of transit should be necessary. I do not think that the ants of the one nest were stealing workers from the other nest, for they acted quite openly and were not treated as enemies, nor did the transferred workers make any resistance as they presumably would if they were being carried surreptitiously away. Nor could it have been a case of slaves transporting their masters, for both the carriers and the carried were of the same species. I frequently observed this transference on subsequent occasions and found it to be a general habit of this ant. I suspect that it is a modified migration ; a mode of founding a new nest when the 51 A NATURALIST IN HIMALAYA old one becomes overpopuhited. It is possible, though this is only a conjecture, that, as the season advances and the nest is densely thronged from the development of many workers, it becomes essential for the com- munity to expand and found new colonies elsewhere. One or more workers proceed on a voyage of dis- covery and thoroughly explore the vicinity of the nest. Havinc[- found a crevice suitable for the estab- lishmcnt of a colony, the worker returns to the old nest and lays the foundation of the new home by transferring workers one by one in its jaws until sufficient have been carried off to relieve the con- gestion in the old nest and lay the foundation of the new colony. This, I think, is one method by which this species increases its geographical range, though the process is undoubtedly a remarkable one. How- ever, after having hundreds of times seen workers transferred from place to place by their companions for no apparent purpose, I was interested to observe at last worker carry worker for the achievement of a definite object. It is difficult to read the accounts of the habits of ants as observed by our greatest naturalists without feeling some faith in the power of intelligence so often ascribed to these insects. I could see little of such high mental powers in the life of the harvesters, and, in my account of their activities, I have dwelt more on their folly than on their reason. But I look with another eye on this species, for I once carefully observed a wonderful act, which, unless I make a grievous error, I must consider a manifestation of real intelligence. On a cool dry evening I discovered a nest of this CARNIVOROUS ANTS 55 species on the side of a bank bordering a field of Indian corn, and noticed that the earth which the ants were throwing out had accumulated in the form of a steep cone extending base downward from the mouth of the nest. It was like a landslip down the side of a hill, and, whenever an ant emerged with its little load of earth and ran out on to the apex of the cone, the loose sheet of earth crumbled away beneath its little feet and it tumbled down the slippery cone. The position of the ants at each exit from the nest resembled that of a man on the snow-slope of a mountain in imminent danger of losing his foothold and rolling down into the valley. The next evening, on visiting the nest, I found that the ants were adopting a wonderful and most ingenious method of overcoming their difficulties by making the ground so firm and resisting beneath their feet as to prevent their fall. One energetic worker had been detailed to collect pebbles from the foot of the cone, to carry them up the slope and build a level platform of stones over the apex of the cone just outside the mouth of the nest. As the workers emerged they now no longer moved over the crumbling and slippery earth, but over the firm and secure platform of pebbles. I watched the ant in this strange, intelligent labour. Down the slope it hurried to search for a suitable pebble. Backwards and forwards amongst the larger fragments, which by their weight had rolled to the very foot of the slope, it rushed about in enthusiastic haste. It was now digging in the ground for suitable fragments, now turning over the pebbles, now testing the weight of the larger stones or attempting to drag 56 A NATURALIST IN HIMALAYA those too heavy for its strengtli. It was never content to take the first pebble that offered, but was continually selecting as though choice was an important factor in the perfection of its work. Back again to the platform it struggled with the chosen pebble ; up the slippery cone it toiled, now pushing, now dragging its heavy burden. Ever stumbling, often slipping down the crumbling slope, it laboured on in its persistent toil. So great was its energy and determined its efforts that it seemed to recognize the importance of its task. Hour after hour it laboured on. Repeatedly it re- turned for pebble after pebble. No other ant ever relieved it ; none ever shared its monotonous toil. All alone it struggled to build a platform of pebbles to save its fellow-creatures from misfortune. The platform consisted of a layer of stones spread over the apex of the cone outside the entrance of the nest. The worker did not cast down its burdens haphazard, but selected a suitable place for the deposit of each load, and often carried its pebble all round the mouth of the nest before it was satisfied in its choice. Thouorh the other workers took no active part in fetching pebbles or building up the platform, yet they rendered a milder form of assistance, for as they emerged from the nest in their work of excava- tion they occasionally dropped a few fragments of earth between the pebbles of the platform, and this served to cement the mass. I thought I would help the solitary and laborious worker in its strenuous task, so I added a few pebbles to the platform, but the other ants would have none of this interference, and immediately seized my pebbles in their jaws and hurled them down the slope. I think CARNIVOROUS ANTS 57 that they recognized them by the smell of my fingers, for two pebbles which I did not touch but added to the platform on the point of a knife were allowed to remain. I know the danger of applying a human motive to the behaviour of any insect, yet I could not escape the impression that the building of this platform of pebbles was the most remarkable instance of division of labour in an ant community that I had ever seen and the strongest testimony to their possession of intelligence. In the mountains of Kashmir I have seen a narrow path crossing a dangerous landslip and a Kashmiri workman building up a rampart of stones to prevent the traveller from losing his foothold and falling down to his destruction. That certainly would be described as an intelligent action on the part of the workman. Nor can I see much difference between the mental attitude of that laborious little ant which spent hour after hour building up a platform of stones to save its fellow-ants from tumbling down the slope and the mental condition of the Kashmiri workman who laboured to build a stony rampart to prevent his fellow-creatures from rolling down into the valley. This wonderful method of building up pebbles at the mouth of the nest is also undertaken by them under different conditions. I have seen a nest so situated that the earth thrown out by the ants formed a circular hill around the aperture, and the excavated earth tended to fall back into the nest. But the ants overcame the threatened calamity by detailing one of their number to build a rampart of stones around the opening of the nest inside the circular hillock and. 58 A NATURALISE IN HIMALAYA so prevent the excavated earth from rolling backward into the nest. All this seems intelligent. It resembles the act of a rational being. But in the midst of this seeming intelligence I must give an example of their utter folly. I have mentioned that these ants so divide their toil dial certain workers are detailed to remain outside the nest for the very important duty of carrying off the pebbles and sweeping away the fmer refuse so as to prevent it falling back again into the nest. But I discovered a nest situated on the face of a steep bank three feet above the level ground. The ants were engaged in excavation. Each ant carried out its little load, conveyed it about six inches down the bank and then laid it against the steep side of the bank, from where it, of course, tumbled down to the level ground. That in itself was folly, the same folly as the harvesters, for the ants would have saved themselves much unnecessary labour had they dropped their loads from the aperture of the nest and not carried them six inches down the bank. But what utter folly. What apparent absence of the first rudiments of intelligence when I looked at the mound of excavated earth three feet below on the level ground. There I saw six busy workers earnestly engaged at work on the mound. Each was hurrying backwards and forwards picking up the pebbles and carrying them away to the edge of the mound, digging and uprooting the larger fragments of earth and sweep- ing back the finer dust with such energy that one might think it was in imminent danger of tumbling back into the nest, Assuredly the an^s did think so, CARNIVOROUS ANTS 59 yet the aperture of the nest was three feet above them. So great was their folly and so impulsive was their instinct that they found themselves driven to indulge in the useless labour of clearing away the fragments from a nest into the aperture of which they could not possibly fall. And thus does folly seem to contradict intelligence and ignorance to clash with reason. Would that we could know what was working in the insect's brain when it built up the valuable platform and when, on the distant rubbish heap, it expended its energies in useless toil. Why is it now intelligent, why now foolish ? Why these inconsistencies ? For in Nature there are no real contradictions ; all moves by unalterable law. CHAPTER V COMMUNICATING AND OTHER ANTS Phidolc imiica — Mode of attack — Power of communication — Experiments on faculty of communication — Sense of smell — Every individual in nest differs — Division of labour— Attitude of Crc mas togas ier — Migrations oi Acantholepis — Sexual forms oi Camponotus. The power of ants to communicate intelligence one to another has been at different times affirmed and denied. I have shown how feeble is this power in the Indian harvesters, nor does it seem much more highly developed in Myrmecocystus. It is therefore instructive to consider another species in which this faculty is perfected to an astonishing degree and on which the existence of the community essentially depends. A little ant, widely spread through Continental India and ascending to the Hazara valley, is known to science as Phidole mdica. I will mention this species with some detail, as I have seen no ant in which the power of communication is developed to so hi(jh a degfree. It is clear to the most casual observer that two very different kinds of workers exist in a nest of the Phidole. There are the soldiers and the smaller workers. The soldiers are few in number, strong and massive in their general build, while the smaller workers are slender, more agile, and swarm about the nest in hundreds. Nor do we see any intermediate gradations connecting the two different m COMMON ANTS OF HAZARA. I and 2. Phidole indica. Soldier and smaller worker. 3 and 4. Camponolus compyessus. Sexual form and worker. 5. Acantholcpis frauenfeldi. [Face p. 60.] COMMUNICATING AND OTHER ANTS 61 classes. They are quite distinct in build, and we shall see that they perform different functions. The soldiers seem to be in about one to five hundred of the smaller workers. Each possesses an enormous square head, large out of all proportion to its slender body, and severed above by a deep median cleft. It is of a dark brown colour with a light red thorax clothed in a few pale hairs. From the thorax a pair of sharp spines projects upwards, and behind is attached a glossy, almost black abdomen. The smaller workers are scarcely one-eighth of an inch in length, not very much shorter than the soldiers, but distinctly less powerful and robust. I do not think the head of a smaller worker can be one-tenth the size of that of a soldier, nor has it the peculiar deep cleft that nearly severs the head of a soldier into two separate lobes ; though for some reason, possibly connected with its more highly developed functions, it possesses distinctly longer antennae. I will pass immediately to the power of communica- tion in this species, which is remarkably acute. These ants are carnivorous and capture insects and larvae alive. The workers are so very small that by their individual strength they can effect little. It is only by the combined efforts of the whole community, under the direction of the soldiers, that a capture is made. As soon as a worker discovers a caterpillar or other suitable material for food, it proceeds to make a care- ful examination of its prey. It runs all over the caterpillar, exploring it with its sensitive antennae, shaking it with its jaws and attempting to drag it to the nest. The worker, satisfying itself that the dis- 62 A NATURALIST IN HIMALAYA covcry is suitable for storaj^e and finding the removal of it beyond its own weak efforts, hastens off to the nest in j^reat excitement and by the shortest route. It meets another worker on its path ; their antennae meet ; the second worker is imbued with the enthusiasm of the first, has received information of the discovery and hastens off to the insect. A third, a fourth, and possibly more workers are similarly informed on the route and all hurry away to lend their assistance. But the excited discoverer hastens on to the nest. Now it has reached the entrance. It enters and is lost to view. In a few seconds a swarm of rushing, bustling and excited ants, led by a number of ferocious soldiers, come dashino- headlono- from the nest. From the way they are all lying in readiness just within the door and emerge at the same moment in one body as though they were awaiting a call for aid, I have no doubt but that these ants so divide their labour that certain workers are detailed for the duty of discovering food, and others, under the guidance of the soldiers, are under orders to remain in permanent readiness within the door of the nest to hurry out and render assistance when news arrives that a discovery has been made. The news has come. Out they swarm in a dense throng preceded by the soldiers. Without the slight- est hesitation they hurry over the ground, passing and repassing one another in their excited haste. In amongst the stones, round the fallen leaves and stems of grass they retrace the track of the discoverer. They have reached the caterpillar. Round about it they collect in a struggling and ferocious swarm. They cluster over it in hundreds, cling into its COMMUNICATING AND OTHER ANTS 63 head and back, and seize on to its limbs ; but it is at the tail of the larva that they make the sternest attack. There they firmly attach themselves with their minute jaws while with their hind legs they cling to every pebble so that the larva in the en- deavour to make good its escape drags behind it a little hillock of pebbles. These impede its progress and give the ants time to bring up reinforcements to the attack. On all sides they besiege the larva, which tries in vain by violent contractions to throw off its enemies. The battle orows hot and fierce. The caterpillar in its struggles now gains the mastery, but ants hurrying on in increasing numbers gradually overpower it. Workers, at intervals, retire from the battle and hasten back to the nest at the greatest speed to call out more reinforcements and hurl them into the fight. The caterpillar weakens ; it cannot face these repeated additions to the strength of its foes. It is overwhelmed by the force of numbers, soon becomes exhausted, and then lies at the mercy of the ants which, clinging in a body round their powerless victim, drag it slowly to the nest. I have often watched a contest of this nature in which the prey was almost always vanquished. But the strangest thing I observed in this connection was that, not only did the ants remove their victim larva, but, in addition, the little stones and fragments of grass that had come in close contact with the body of the larva were also dragged deliberately to the nest. I killed a grasshopper and moistened a number of small stones with the juice from its body and then gave them to the ants, and these stones were also removed to the nest. It appears that the ants carry 64 A NATURALIST IN HDIALAYA off to their nest the fragments of stone and grass under the impression that they are actually edible sub- stances, though in reality they have been only moistened externally with the animal juices. I was surprised to find that a group of insects possessed of such remarkable instincts should have been so hopelessly misled as to confound animal tissues with stones. r>uL I must return to their power of communication by virtue of which a single ant can inform the nest of its discovery of prey, can launch the awaiting army to the attack, and can, if necessary, return again and again to call successive reinforcements to its aid. This, I think, is a true communication, a real transfer of information from one ant to the remainder of the body, and as a consequence of which, a distinct series of activities result. Wonderful as is the instinct of communication and essential as it is to the life of the community, yet like every instinct it is imperfect and capable of confusion. I gave a dead insect to a worker. The busy little creature hurried back with the news of its discovery and in a few moments the swarm came rushino- to the scene. I then removed the insect, and the ants, finding nothing, returned to the nest. I then placed the insect on the opposite side of the nest. A worker soon discovered it and brought back the news. Again the swarm issued from the nest, but confusion almost at once followed. Many ants hurried along the correct track and found the insect, but others, as though still confused by the memory of their previous exit, hastened to the spot where the insect was first placed and searched for it in vain. On another occasion I have observed the instinct so confused and the swarm so lost in its I COMMUNICATING AND OTHER ANTS 65 efforts to find the object to which k was summoned, that the original discoverer, previously marked with a speck of paint, has had again to return to the nest and call out the swarm a second time. The ants are sufficiently careful not to empty com- pletely their nest when the swarm emerges. The whole strength is not lost in one effort. A reserve swarm is left in readiness within the nest to be called out should information be received of a second discovery while the main swarm is engaged in over- coming the first. Or should the contest be severe, the ants will have reinforcements in readiness to advance and support their fellows. Like the prudent commander' of an army, they rarely throw the whole strength of their force at one moment into the struggle, but rather keep a strong reinforcement in reserve to be sent forward should necessity arise. This, in truth, is a wonderful power of communica- tion, for not only does the worker supply the informa- tion that it has discovered something, but it can communicate to its fellow-workers the place where the discovery has been made. The other ants which I have described could never have transferred one to the other such definite communication as this. The process is worth further investigation, so I describe the following observations and simple ex- periments to shed some light on the manner in which I believe it works. At first it appeared possible that the returning ant might have caused the excitement in the swarm and urged them into activity by bringing into the nest a tiny fragment of the discovered treasure. But I am certain that this was not so, but that the communication was a real transfer of 66 A NATURALIST IN HIMALAYA information. I never could detect the slightest trace of a fragment of the insect in the jaws of the returning ant, and sometimes the discoverer would merely examine the tarsus of the insect before returning to call out the swarm, and from the hard tarsus it could certainly not tear away a fragment. JNIoreover, I was later able to convince myself that the swarm was not excited by the sight or smell of a particle of the prey, for I found that certain workers in the community were quite unable to communicate, and though they returned again and again with fragments of the dis- covered insect, they did not in the slightest degree excite the swarm, nor were they able to give any information of their valuable discovery. In some way or other it is within the power of a single worker, independent of anything it may carry to the nest, to convey information to a swarm of other workers, and to announce to them the valuable fact that " I have discovered food." But how this process of communication works, by what mechanism the one ant transmits its information or the other ant receives it, I find it not only difficult to understand but even to investicfate. I will therefore consider in more detail the second link in the process, as I find it more intelligible ; namely, the power possessed by the solitary ant of directing the struggling, hurrying swarm straight to the discovered insect. At first I thouofht that the ant returnino; with the news led the swarm from the nest and directed them along the true road ; that the discovering ant was the leader and that the swarm followed in its train. It was necessary to mark the discoverer with a speck of paint in order to investigate the matter. This COMMUNICATING AND OTHER ANTS 67 is a difficult operation. The workers are so tiny, so agile and quick in their movements, so excited and easily frightened that the slightest touch fills them with alarm. At last after many days and innumer- able unsuccessful attempts, I succeeded in marking three ants without terrifying them out of their senses. I found that the worker returning with the news of the discovery emerged from the nest, not at the head of the issuing throng as though it was acting as a leader, but appeared in the midst of the swarm. Nor was it essential as a guide to the true road which led to the discovery, for many of the ants in the issuing swarm outran it and came first to the treasure. Undoubtedly its presence in the swarm was a great assistance, for many of the ants would rush up to the marked ant, rub their antennae against it and then hasten off to the insect in the greatest excitement as though they had gained valuable information by contact with the discoverer. But it is certain that the discovering ant, once it has given information, is no longer essential as a guide to the swarm, for I captured one of the marked ants at the moment of its emergence from the nest, and the swarm, in its absence, had no difficulty in finding the insect. Since the returning ant cannot act solely as a guide and since, indeed, its presence seems to be no longer essential once it has passed its information to the awaiting throng, it was difficult to form any other conclusion but that the issuing ants found their way to the treasure by retracing the scent of the returning ant. I think that this can be the only explanation, for when the swarm is hurrying to the discovery it 68 A NATURALIST IN HIMALAYA certainly does follow back along the track of the discovering ant, but if the finger be drawn across the track so as to disturb the scent, then the swarm of ants will be thrown into confusion. The line drawn by the finger will form a regular barrier over which the ants will cross with difficulty, or at which they will lose their way and return to the nest. Members of the issuing swarm, I have said, repeatedly communi- cate with the discoverer, and they act thus, I believe, because they are following the scent of the discovering ant and wish to reassure themselves that they are on the right scent by again testing the odour of the ant. For this odour is a guide to the true road. Fig. I. — Experiment with Communicating Ant. But a few simple experiments will confirm the matter. If a dead insect be fixed to the top of a stick standing erect on the ground, and a worker be placed on the insect and then allowed to run down the stick, return to the nest and inform the swarm of its discovery, then the issuing swarm will have no diffi- culty in finding the insect in this strange position. But if, after the departure of the worker, the vertical stick be replaced by another similar stick, then the swarm will be thrown into confusion at the base of the new stick owing to the scent being there lost. Now if F (Fig. i) be the discovered food, N the nest and FN the returning path of the discovering ant, and if, on that path at the point A, the ant be raised from the ground and transferred to B, then the swarm COMMUNICATING AND OTHER ANTS 69 on emerging from N will proceed rapidly to B, but at that point will be thrown into confusion and unable to advance further owing to the gap in the scent between B and A. Those who believe in the hypothetical sense of direction, supposed to guide ants in their wonderful journeys, might suspect that it was some strange directive power, inexplicable to us, that impelled the swarm along the true road. I do not think that this is the case, for I placed a dead insect on the end of a horizontal stick directed to the west and allowed the worker, after making its discovery, to run back along the stick on its way to the nest. Then, during the absence of the worker, I rotated the stick in a semi- circle so that it was directed to the east, but the swarm on reaching the foot of the stick were not confused ; they hurried along it without hesitation though its direction had been reversed, I feel confident that their wonderful power of scent is their true guide. No other explanation seems to fit the facts. I think that the ants within the nest recognize the distinctive odour of the worker that brings the news, and can thus retrace the track which that particular worker has followed. The information which the returning ant communicates to its fellows appears to be this, " I have found food ; retrace my scent and you will find it." When observing the harvesters, I was driven to the conclusion that each individual in the community was capable of distinguishing its own odour from that of every other individual in the nest and that, there- fore, each ant must have a distinctive scent. Here we are forced to a similar conclusion, for the swarm 70 A NATURALIST IN IIDIALAYA must distinguish the specific odour of eacli returning worker, and if so, then every single worker must have a distinctive scent. How marvellous are the manifold works of Nature, and what extraordinary conclusions are we forced to form when we endeavour to penetrate the secrets of her work. It is interesting to contemplate a host of hurrying ants, to see them advance in mass to the attack, do battle with the foe and drag it to the nest. It is instructive to witness their strategy, their system, their organization and the union of all for the general good ; but few thoughts can be more wonderful, few can fill us with a deeper sense of the complex scheme of Nature than the knowledge that, in a nest, each single one of these thousands of tiny insects is known to every one of its fellow-creatures. Each little worker seems but a moving speck lost in a swarm of insect life, but it is a speck unlike the thousands of other specks ; it has its own distinct characteristics, its own individuality ; it distinguishes separately each one in the countless multitude and each one distinguishes it. A shepherd can distinguish each sheep in his fold ; man can see differences in all his fellows ; but it seems a far more wonderful thought that this swarming, hustling throng of insects should possess the faculty of individual recognition. All these ants must differ ; there can be no two quite alike. The thought arises as to how far through living nature may this difference extend. At times we may look into the skies and see birds congregated in tremendous flocks ; we may peer into the ocean on vast shoals of fishes; we may survey a desert for hundreds of square miles all green with swarming locusts. Do these all differ, though to us COMMUNICATING AND OTHER ANTS 71 all alike ? If analogy is any guide, then surely our reason would lead us to suspect that as man differs from his millions of fellow-men, as every sheep is known to its shepherd, as in the multitude of busy ants all the members are unlike, so this endless difference may extend through every path of organic nature, even through that most amazing profusion of fertility, the dense locust swarm. How wonderful is Nature to mould her creatures all unlike and collect them into groups of great resemblance. That none shall be identical may be as inexorable a law of Nature as that like produces like. It is only the smaller workers that possess the power of bringing information and calling out the swarm. The soldiers rarely hunt about for prey ; their duty is to remain indoors and await the news brought by the smaller workers. Their great strength is their most valuable asset. To the community they are useful, not for discovering food, but for fighting battles, directing the swarm, and dragging insects to the nest. On two occasions I found a soldier hurrying about outside the nest and gave it a dead insect. Now if this had been an ordinary worker it would have hastened to the nest with the news and the awaiting swarm would have poured out through the gate. But the soldier could not undertake that duty ; it remained for ten minutes dragging vainly at the insect and running round about it, but never attempted to call out the swarm. The second time the dead insect was rather bruised, and the soldier tore off a fragment and carried it to the nest. Again and again it returned for another fragment, but always singly. Its excited state 72 A NATURALIST IN HIMALAYA and the presence of food in its jaws had no effect on the awaiting throni^^ It seemed to possess no power of calHni^ out the swarm or of L^iving information of its valuable discovery. But the division of labour in this community is brought to a still higher degree of perfection, for not only is the labour distinctly divided between the larger and smaller workers, but also different tasks are assio-ned to different groups of the smaller workers. I draw this conclusion from the following observation. When a nest has been fully excavated and the duty of the whole community is to collect food, then every ant appears to render aid when the call arrives. But one evening I discovered a nest which was still under- going excavation. Certain of the ants were carrying out their litde loads, while others were running about outside the nest. I gave a dead grasshopper to one of the workers and expected that, on arrival of the news of the discovery, the work of excavation would cease and all the ants would hasten to the spot. But this was not the case. The swarm emerged and attacked the grasshopper, but the workers engaged in excavation took no notice of this rich discovery, but continued their monotonous toil. The swarm dragged the grasshopper to the nest, but the insect was too large to enter the aperture and remained fixed, half in and half outside the nest. Round about the gate was this seething swarm of ravenous workers, all tearing and dragging at the insect in their excited efforts to draw it past the obstacle, but still the workers engaged in excavation took no notice. At every exit each little excavator had to force its way through the greedy throng and sometimes had even to climb COMMUNICATING AND OTHER ANTS 73 over the body of the insect, but it never interfered in the efforts of the swarm. It recognized that the labours of the community had been divided, that it was its office to engage in the humble duty of ex- cavation, while to others alone was assigned the more adventurous work of capture. In the defence of the home they also divide their labour. To the soldiers is the chief glory of the battle. I have watched nests with stalwart and ferocious soldiers posted at their gates. They stand guard over the entrance, ready at a moment's notice to hurl a reckless attack on an invader. In this species the soldiers are very pugnacious and some- times exert an autocratic tyranny over the smaller workers ; for I have seen them, in the exertion of their authority, crush and mangle in their powerful jaws the workers of their own nest and rend them into fragments. In their migrations, likewise, we see the same principle in force, each one to its own duty. The main burden of toil falls on the smaller workers. It is they alone that transport the larvae, and they often carry their companions from nest to nest. The soldiers carry nothing. They are not humble toilers, but are the directors of the transport. They are the aristocracy of ant life. They hurry out of the nest singly and at intervals with a throng of laden ants following in their rear ; and as each powerful soldier hastens along the migrating line, it looks like an officer leading and directing his company of men. Nor do the soldiers return again to the old nest. The smaller workers, once they have deposited their larvae in the new nest, hasten back for a fresh burden. 74 A NATURALIST IN HIMALAYA but ci returnini^ soldier is never seen. It, no doubt, busies itself with important duties within the new nest, but takes no further part in the migrating line. And as sometimes happens in human society, the directors of the community, the oft-reviled aristocracy, become neglectful of their great duties and sink into a contemptible idleness ; so do the soldier ants, the aristocracy of this insect labour, appear sometimes to neglect their duties, and, instead of taking an active part in the direction of this migrating stream, resign themselves to abject laziness and permit the busy little workers to carry them from nest to nest in their jaws. I must now pass from these wonderful Phidolc ants to consider other species. I could never tire of studying them, not in confinement, but on the mountain sides, in the fertile fields or the sheltered glens. I loved to watch them divide their labour, each one to its own task, and to test and retest that remarkable intercourse by which they communicate one with the other. But because these ants communicate, it must not be presumed that all ants communicate. From the study of a single species of ants the presence of the power of communication has been asserted and denied for this whole tribe of insects. The fact appears to be that one species may possess the power and another not possess it, and it is quite unjustifiable to affirm or deny the presence or absence of any sense from the study of any single species. For do we not here find the absence and presence of the power of communi- cation amongst the different workers of the same species ? And what is true for the power of com- COMMUNICATING AND OTHER ANTS 75 munication is equally true for any other faculty. Harvesters have an acute sense of smell ; in other ants it is almost absent. M. setipes detects by sight the slightest movement, harvesters have a dim, limited vision, other ants are totally blind. By communication these ants live ; it is the mainspring of their existence. Could they not com- municate they could neither capture their prey nor overpower it and drag it to the nest. But is there any real intelligence in this essential act of life ? I could never see that there was. The ants were im- pelled by a power far greater than their own feeble minds ; they neither knew what they did nor did they know why they did it. I have but few remarks to make on the remaining species of ants that occur in this valley. A common genus, Cremastogaster, which frequents the trunks of the trees, has the peculiar habit of turning up its heart-shaped abdomen so as to stand out at right angles to the rest of the body. When the ant is running about excitedly, the pointed and projecting abdomen gives the insect a somewhat terrifying appearance, and suggests that it is prepared to sting savagely on the slightest provocation. As in the case of the Myrmecocystus, I first considered that the peculiar attitude adopted by this genus possessed the useful function of suggesting to insectivorous enemies that it was a ferocious creature and that they had better abstain from attack. I doubt, however, if this explanation is correct, for I have observed that another species, Camponotus coiupressus, which does not usually adopt this attitude, will, when descending a tree-trunk head foremost, allow its abdomen to fall 76 A NATURALIST IN HIMALAYA downwards over its back under the influence of gravity until its position exactly resembles that of a Crcmasto- gastcr ant. A large abdomen, under such insufficient muscular control as to have its position affected by the stress of gravity during the ascent and descent of the tree-trunk, must to some extent diminish the stability of the insect. And I suspect that a Creinastogasier ant, which is continually moving up and down the trunks of the trees, has found it more advantageous to its stability and balance to maintain its abdomen permanently in the position that gravity would fix it during the descent of a tree, rather than drag behind it an unwieldy mass ready to sway about in every direction that might always serve as a threat to its equilibrium. The adoption of this attitude might be expected to produce anatomical changes in the struc- ture of the ant. This seems to be the case, for the narrow pedicle, that in most ants connects the thorax to the middle of the front of the abdomen, is in this genus attached not to the middle but to the upper margin of the abdomen. An attachment of this nature permits the unusual attitude to be more easily adopted. The migrations of ants often display the plasticity of instinct in the species and the power of the ants to modify their behaviour to meet unusual conditions. One small and agile little ant, Acantholepis fraiienfeldi, seemed to be continually in a state of migration (see Plate, p. 60). After every shower of rain a stream of workers might be seen hurrying from an old to a new nest, all heavily laden with larvae, I suppose that the rain, flooding the nest, makes it uninhabitable for the ants, and they are forced to remove to drier quarters. 1 he ants often do not migrate to any great distance ; COMMUNICATING AND OTHER ANTS 77 the new nest may be established six, eight or ten feet away. They do not necessarily migrate in one body all at one time, but those which carry the larvae to the new nest may continue to return to the old nest again and again to convey another burden. One day I watched them migrating in a long file and entering the new nest by four small apertures. I sealed up with stones these apertures in order to observe what the ants would do with their precious larvae. After a short period of great excitement and commotion, the workers carrying larvae turned away from the closed doors, retraced their steps for a short distance towards the old nest, and then branched off to one side in the direction of a small heap of withered grass. Beneath this grass they deposited their larvae, in order presumably that they might not become injured by exposure. They then returned to help in the removal of the obstruction. Now as each ant turned away from the barred door to conceal its larvae, it frequently passed and appeared to communicate with other ants bearing larvae to the new nest. Yet it never appeared to be able to convey the information to them that the opening of the nest was barred and that the larvae should be stored beneath the heap of grass. Each ant had to proceed right up to the obstruction and investigate for itself the unusual state of affairs before it could deposit its burden and help in the task of demolition. On another occasion, during a migration of the same species, I killed a number of the migrants close to the entrance of the nest into which the ants were carrying their larvae. This filled the ants with intense alarm ; there was now no attempt to hide the pupae until the 78 A NATURALIST IN HIMALAYA danger was removed. Migration at once ceased and the larvae were hurried back to the old nest. A number of ants remained about the aperture searching in all directions for the cause of the calamity. After an hour of fruitless search they must have concluded that all cause for alarm had disappeared, for the ants began to emerge with their larvce from the old nest and the migration again continued in a steady stream. Thus can the migrants modify their behaviour. If they meet with an obstruction, they conceal their larvse and break down the opposing barrier ; if they imagine danger is at hand, they cease their migration and retire to the deserted nest. As rain stimulates migration, so also does it awaken the sexual forms which, on emerging from the nest, soon seek union. This takes place under different conditions in different species. In the large Myrme- cocysttis setipes union sometimes occurs on the ground near the mouth of the nest shordy after the males and females escape. It may therefore enjoy no nuptial flight. This is not so with the harvesters, for the males and females of this ant fly away independently, and the probability of union must in this species be more remote, as it will depend on a chance meeting between the opposite sexes at a distance from the nest. The sexual forms of other ants congregate in the air in a regular swarm. The males and females of one of the smaller species of the Myrmecince collected round me one morning in June as I wandered through the fields. They moved through the air like a cloud of insects, and persisted in alighting on my head and shoulders, after which act union occurred. The life of the male after it leaves the nest must be COMMUNICATING AND OTHER ANTS 79 extremely short. One evening- I observed that a number of the sexual forms of the larg^e black Indian ant, Camponotus compressus (see Plate, p. 60), were flying about the lamps, so that it was clear that a nuptial flight had emerged. The following morning I found that the ground was strewn with thousands of their dead bodies, all of which seemed to be males. Such is the flickering life of the sexual male ; just a few hours of sunlight or perhaps a single night ; just a sufficient time to perform the sexual function for which sole duty alone it lives. The workers bestow much care and attention on the sexual members of the community. One evening after heavy rain the males and females of the species Ca?Hp07iotus dolendiis had collected, preparatory to flight, in a swarm on the ground close to the gate of the nest. The workers, chiefly those of the large, strong soldier type, formed a ring of defence around them like a bodyguard of infantry drawn up in battle- order to repel an attack. I disturbed one of the workers, and soon the whole community was thrown into alarm. From the intensity of their excitement it was clear that the soldiers recognized the sanctity of their charge. The males and females, being the peaceful and inoffensive members of the family, hurried away into the security of the nest ; but the more stalwart workers, in their position as protectors, scattered savagely in all directions to seek out and come to battle with the foe. After this alarm had passed, the sexual forms again emerged and wandered away into a tuft of grass a few feet from the nest. As nightfall approached, the workers became restless. It was the hour when the 80 A NATURALIST IN HIINIALAYA ants OLiijjht to have been retiring to rest, yet all the winged forms on which they bestow so much attention lay scattered about in the grass. It was obvious that the sexual forms had no intention of returniuLi' home before dark. And this is in itself interesting, for the workers in their daily labour retire each evening to the nest ; but the males and females, not taking part in the routine of work, felt no instinctive impulse urging them to retire. When darkness fell they were helpless. They had never been in the habit of return- ing to the nest before dark ; they were therefore quite unable to do so now, and were prepared to remain outside for the night. But their protectors would have none of this. Though in the sexual forms instinct failed, the workers would meet the needs of the case. They were deter- mined not to leave their precious care exposed, and they soon solved the problem. They formed a line between the tuft of grass and the nest ; workers hurried out ; each seized a prospective parent in its mandibles, clutching it by the back of the neck, and carried it off to the nest. It was the males alone that required transport. For the females example was enough ; they seemed to possess a stronger instinct of self-protection, for they found their own way back to the nest. The males received very bad usage during the process, yet they calmly resigned themselves to their fate. The workers either dragged them roughly by the neck over the stones, or pushed them forward with such vehemence against sticks and slates and tufts of grass that it seemed as though their heads would be severed from their bodies. But they made no resist- ance. They folded their wings against their sides, COMMUNICATING AND OTHER ANTS 81 curled up their slender legs, passively surrendered their lives to the care of their sterile sisters, and sub- mitted to the hardships of the journey until they were lodged safely in the nest. Thus do the workers guard and cherish the sexual forms on whom the future life of the race depends. How variable are the habits and instincts of ants, even among members of the same nest. I have endeavoured to tell something of them as seen in the common species of this valley. But it matters not how their labour varies, we always see the same underlying principle of the subordination of each one to the well-being of all. The individual is nothing ; the community is supreme. The single ant is lost when separated from the formicary. So organized is the social structure, so dependent is each ant on its , fellows, that when it finds itself alone it is helpless. It cannot even live unless it again joins the throng. Its brain, though infinitely complex, exists not for the single ant, but as an integral part of the whole com- munal mind. Each individual is as a single cell of which the commune is the developed being ; each brain is a single atom submerged in the restless spirit of the swarm. CHAPTER VI GEOMETRICAL SPIDERS Home of spider — Species under discussion — Constitution of colonies — Construction of snare — Emission and structure of the first line — Mechanism in construction of radii — Mechanism in hub — Mechanism in temporary spiral — Mechanism in viscid spiral. The most ancient beds of the earth's crtist involved in the upheaval of the Himalaya mountains are thick masses of primary slates into which the molten granite has intruded. They rise in Hazara into rounded hills with smooth summits and sides crumbling to decay. Little verdure clothes them. A few pines may cluster on their peaks, or thorny bushes collect in their more sheltered glens. Their flanks are hidden in a coarse mountain grass, brown and parched in the dry sultry months of summer, but changing into a pleasant green after every fall of rain. The moisture that freshens their surface likewise hews them to their present shapes. Streams eat into their fissile sides and erode valleys between their rounded backs. Softer and harder strata meet the waters as they cut deeper into the rock, and each changes the nature of their flow. As the consistency of each bed alters or obstructs it, the stream stagnates into a sluggish pool or splashes onward in rivulets and cascades. These streams are the home of the geometrical spiders. Over the running water, more often over the transparent pools, these skilful architects extend their 82 GEOMETRICAL SPIDERS 83 fragile snares. Suspended on either side from a tuft of grass, a thorny bush or a bare slab of shale, the fine silken webs span tight across the stream. The site is a perfect one for the Epeira, for here flies and other tiny insects abound which, as they hover over the water, fall entangled in the well-laid snares. Two species of the Epeiridcs haunt these streams. They belong to distinct genera and differ greatly in appearance. The more common of the two is Araneus nauticus, a brown globular little spider from a quarter to half an inch in lengrth. Its narrow flat head sunk low between its limbs is scarcely visible. But on the upper surface can be seen the six black shining eyes, and projecting in front are a pair of sharp-pointed ponderous jaws. Behind the head is the inconspicuous thorax clothed in thick greyish hairs, with the limbs, banded in black and yellow, spreading out on either side. Overhanging the thorax and forming the larger portion of the spider, is the massive heart-shaped abdomen. A thin coat of hair covers the abdomen, while its upper surface is marked with a yellowish cross. The other spider is a species of the Tetra- gnatka, not so common as the Araneus, but possessed of very similar habits. It is strikingly different in appearance, with a narrow elongated body, and a small head supporting its massive jaws. A line of minute teeth strengthen the jaws on the inner side, while their distal ends are armed with a long pointed fang. Its legs are unusually long and slender, so that the spider seems ungainly in its motions. It has the peculiar habit of extending its legs backwards and forwards, pressing them close together so as to bring them in line with its body. 84 A NATURALIST IN HIMALAYA Thou''h foreiirn to the usual habits of spiders, these two species Hve together in perfect harmony. Most spiders prefer a sohtary existence, desiring no com- panions, devouring every intruder or driving it savagely away. Yet these spiders often follow a gregarious life, interweaving their snares into one wide common sheet. It is not unusual to fmd half a dozen of these snares all connected by their foundation-lines, and even those of the two species sometimes intermingle. I once found a collection of twenty-one snares all communicating one with the other, and both Araitetis and Tetragnatha were represented in the colony, and they all lived together in complete harmony. Spiders in other countries sometimes unite into similar com- munes, Darwin tells us that in South America a species of Epeira congregates in small colonies so as to encompass large bushes with their united nets. He remarks on the singular fact that this gregarious habit should exist in such bloodthirsty and solitary creatures. Peace exists in these colonies over the streams. The spider from one snare seldom invades that of its neighbour ; should it by mistake cross the frontier, it is immediately made aware of its error and ordered to be off. For the spider in the invaded snare throws the whole structure into a state of rapid vibration, and the intruder, feeling this, instantly turns about and returns to its own territory. From year to year the numbers of these spiders vary. A dry summer results in a scarcity of insects, and this is a direct cause of the rarity of the spiders. A wet season supplies an abundance of snares. And not only are the spiders affected through the medium of the insects, but so also are the insects that prey on GEOMETRICAL SPIDERS 85 insects. In a dry season there is a marked diminution in the drasfon-flies and the robber-flies that hunt insects on the wing. Similarly will the insectivorous birds be reduced in numbers, and each species will affect each other species in the complex web of life. The mode of construction of the snare is similar in these two species of Epeira ; yet it is obvious that Aranetis has a decided preference for suspending its web in the vertical and Tetragnatha in the horizontal plane. This wonderful architecture has often been described, yet I here take the liberty of again display- ing the method of work in order that the subsequent experiments that I made on the snare may be found the more intelligible. I isolate an Araneus on the tip of a blade of grass standing in a shallow pool. The spider is cut adrift from land ; it is marooned and cannot escape. I sit down to see how it will act. The hour of work is at hand, so the spider soon sets about the construction of a snare. A series of successive stages now follows, each stage a definite step in the architecture, a preparation for the succeeding stage. The first essential are some foundation-lines to serve as a framework for the snare. The spider begins. It climbs to the tip of the blade of grass ; it elevates its abdomen and from its spinnerets emits a silken filament to the wind. The light filament is wafted to the shore, becomes entangled in another blade of grass, and the first foundation-line is in place. Back- wards and forwards runs the spider along its line, adding each time a new filament, doubling, trebling, quadrupling the line until it is strong and sound. The first foundation-line is secure. For the second 86 A NATURALIST IN HIMALAYA foundation-line the spider adopts a different procedure. It takes its stand about midway on the first Hne and suddenly drops down suspended on a filament of silk. Perhaps it finds an attachment. If not, it climbs up again and drops down from another point. At length it meets a blade of grass and anchors its second line. It has now two lines with three attachments to stalks of grass, one at each end of the first line and one at the lower end of the second line. By joining these points together with a filament of silk a triangle is formed of three foundation-lines, the simplest form of framework to support a geometrical snare. The spider reinforces these lines with additional filaments until it is satisfied with the strength of the scaffold. This is the first and elemental stage ; the construction of the foundation-lines. I now come to the second step in the architecture. A triangular framework is in position ; or, if suitable connections can be found, a trapezoid figure is more to the spider's choice. Whatever its shape, the spider next proceeds to construct the radii. These are the spokes of a wheel that diverge from a common centre to end at the foundation-lines. The spider constructs them with little trouble. It first runs a line from side to side across the framework. Then, selecting a point on that line which will be the future centre of the snare, it carries a number of lines from that central point to the circumference of the snare. In this way it completes a series of radii, each equidistant from its adjoining radius. Each radius is in accurate position ; all diverge equally from the common point. The second stage is mathematically complete. Now comes the third stage, the construction of a GEOMETRICAL SPIDERS 87 hub. The snare in its present state resembles a wheel. It has a centre, radiating spokes and a rim formed of its foundation-lines. The spokes need some strengthening at the point where they leave the centre ; the wheel requires a hub. This the spider proceeds to make. It winds five turns of a slender filament around and close to the central point attach- ing the filament to every spoke. A hub is thus added to the wheel ; the spokes are bound together at their inner ends and the third stage is complete. The fourth step in the work is the formation of a temporary spiral. This adds a further strength to the snare, holding the radii still more firmly in place. The spider takes four turns round the hub, stepping from radius to radius and attaching the filament every time it passes a spoke. A spiral of four turns, like the hair-spring of a watch, is thus wound about the centre. All the turns are parallel, all accurately placed. The work is perfect and precise. This is the fourth stage in the architecture, the construction of the temporary spiral. The spider now reaches the fifth and most important step in its work, the formation of the viscid spiral. It proceeds to the outer margin of its snare close to where a radius joins a foundation-line. It now commences to wind another and much longer spiral round and round the snare, commencing at the circumference, working towards the centre and attach- ing the spiral at every spoke. To pass from radius to radius it uses the temporary spiral as a bridge. Now this viscid spiral is the vital element in the snare. It is continuous in closely parallel lines from the circumference to the very centre, It is covered with 88 A NATURALIST IN HIMALAYA a highly viscid lluid, while all the other lines, the radii, the hub, the temporary spiral are non-adherent to the touch. It is that part of the fabric that has the power of capture. The formation of the viscid spiral is a laborious task ; it occupies the spider more time than all the rest of the snare. It is a fine and subtle filament, often continuous from end to end. Every line is parallel, and the whole is a wonderful work of Fig. 2. — Diagram of the parts of a Geometrical Snare. (a) Centre. (fi) Hub. ((■) Temporary spiral. ((f) Radius. (e) Viscid spiral. {/) Foundation line. mathematical beauty and perfection. The spider at length completes its viscid spiral. It anchors the end close to the centre and the snare is finished. Such is the construction of the geometrical snare, a work of the most marvellous texture. There are five successive stages in its architecture (see Fig. 2). 1. The foundation-lines. 2. The radii. 3. The hub, I-I •v ■^ til IT. ^ P < < X (I. o (/I W c ■rH fj GJ — . "^ "^ rt ~ u OS" (u ;:; o GEOMETRICAL SPIDERS 89 4. The temporary spiral. 5. The viscid spiral. I have some remarks to make on each step in this work. It is a fabric worthy of our note. The strength of its transparent filaments, the geometrical accuracy of its lines, the subtlety of its device and the unerring certainty of its power cannot but excite our wonder and admiration. To produce such a consummate work needs the skill of a master-hand moved by a geometrical sway. I will endeavour to disclose the nature of this handiwork, to show how all this accuracy is attained. I hope to demonstrate how the spider works ; how it measures its equal angles ; draws its perfect parallels ; secures its equidistant lines ; how it achieves all this mathematical accuracy which, woven into its architecture, makes for the beauty, the perfection and the certainty of its snare. First with respect to the construction of the founda- tion-lines, the fact of most interest is the ingenious manner in which the spider pays out its filament to the wind. The spider does not act altogether haphazard, allowing the filament to trail away from the spinnerets in search of a chance attachment. It shows some method even in this simple act. It supports the thread with the claws of its second tarsus and tests its every quiver and motion. With the filament curved over the tip of its tarsus, it is really fishing for an attachment, using the most delicate of lines and the most sensitive of fingers. But the filament itself is more worthy of notice. It is specially adapted to its peculiar purpose. Not only is it light and slender, fit to be supported on a gentle breeze, but the spider ha^ 90 A NATURALIST IN HIMALAYA in addition giv^en it a special construction by which its buoyancy is still more improved. In the Arancus it is difficult to detect this special peculiarity of the first line. Little more can be seen than the silken thread extending outward from the spinnerets. But there is a large and handsome genus of the geometrical spider known as Argyope, about an inch in length, in which more detail can be seen. If we have the chance to watch an Argyope in the act of emitting the first filament of its snare, we will see that the tip of the line that it gives to the wind is not a single filament but a complex structure. It is divided into a sheaf of the very finest fibrils, each inconceivably light and delicate. These float freely in the air and serve to support the more compact and single thread that follows them from the spinnerets. Thus the first filament of the snare is a highly specialized thread, a long single line ending in a free cluster of the finest, almost invisible fibrils ; a structure beautifully adapted to sail on the wings of the faintest breeze. Even the emission of the first line is worthy of our note. It illustrates the ingenuity of the spider's methods by employing the wind to support its lines, and the exquisite adaptability of its filaments to the varied stages of its work. I come now to the method by which the spider constructs its radii ; a mode of workmanship that has always filled me with wonder at the geometrical powers of this simple creature. It is clear from the beginning that the radii are laid down in no definite order, but in a haphazard manner. Nevertheless they are all equidistant ; all diverge from the common centre with the same perfect synimetry as the spokes GEOMETRICAL SPIDERS 91 diverge from the hub of a wheel. We ask ourselves, how is this symmetry attained ? By what mechanism does the spider measure with such accuracy the same distance between each pair of radii ? Let us watch the spider at work. It has completed the foundation- lines, and is now throwing out its radii. Backwards and forwards from the centre to the circumference we see it hasten. Out along one spoke, back along another spoke, and on each return journey a new radius is secure. For a moment it halts at the centre. Something engages its attention here. It busies itself about the hub. It rotates from side to side. It is examining the radii all round the snare, satisfying itself that in one part they are complete, that in another part they have not yet been spun. We watch with care this examination of the radii. We see that the spider with the tips of its fore legs is feeling and testing the radii just at the point where they leave the hub. We see a pair of legs expand like a mathematical dividers ; the tip of one leg rests on one radius, the tip of the other leg on the adjoining radius ; and it is clear that the spicier is measuring the inter- radial distance by using its legs as a pair of dividers while it remains seated at the hub. The limbs are kept at an even distance and the spider stretches forward to feel all round the snare. Should it feel a radius with the tip of each limb, then it knows that the radii are complete in that segment and are at the correct interval. It then turns to another part of the snare and again feels for the radii. It has now to expand its legs more widely to feel two adjoining radii, and it therefore knows that here the radii are incomplete, Legs expanded the normal width mean 92 A NATURALIST IN HIMALAYA radii accurately placed ; legs too widely expanded mean that a radius or more is absent. Thus the first step in the adjustment of the radii takes place at the centre of the snare. It is here that the spider learns in what part of the snare the radii are complete, in what parts more are to be laid down. It is by this mechanism that the spider rests finally satisfied that every radius is in place. So much for the process by which the spider locates those parts of the snare not yet supplied with radii. I pass now to a second mechanism, that by which the spider measures the correct distance between the radii. This takes place not at the centre but at the circumference of the snare. It follows in this way. The spider at the centre has discovered an interval not yet supplied with a radius. Its legs, acting as a pair of dividers, have expanded two radial-widths. It therefore knows that a spoke is here absent and it must needs supply it. Out along the nearest radius it hastens, paying out its filament of silk. It reaches the circumference where the radius joins the frame. Now occurs the interesting part of the mechanism. The spider takes four paces along the foundation-line, then halts, draws tight its filament, secures it to the frame, and a new radius is in place. It is the four paces along the foundation-line that makes the measurement exact. In this the spider never errs. Every radius is secured to the frame four paces from an adjoining radius, thus all the radii are equidistant and perfect symmetry is attained. It may seem degrading to the exquisite workman- ship of the spider to reduce its methods to mathe- matical terms, To my mind the work appears iriore GEOMETRICAL SPIDERS 93 wonderful by knowing something of the manner of that work. The spider is not degraded because at the centre it can measure equal angles, at the circum- ference equal arcs. Would not man act similarly under like conditions ? Would it not be a simple method of drawing equidistant radii from the centre of a circle to take equidistant points upon the circum- ference and then join them to the centre ? Would it not be a simple method to measure the angles at the centre to see that no radius had been left out ? The spicier has adopted human methods ; it works on geometrical lines. Its limbs are its dividers and its measuring rule. By their aid the snare assumes those accurate proportions that we never cease to admire. Man can do but little better were he faced with the construction of a similar snare. Each would work on similar principles, the one knowingly, the other instinctively. The spider, like man, is a geometer. Assuredly by being so it is not degraded. Rather must we not wonder at similar methods existino- in the highest and the humblest creatures o o so far distant in the tree of life. Before leaving the radii I must mention a little detail with regard to their structure, since it is a special adjustment designed to give them additional strength. Each radius is so constructed as to consist of a double line. The method of duplication takes place in this way. The spider during its examination at the hub discovers an interval where no radius has yet been laid down. It immediately hurries out along one of the radii that bounds this interval and of course pays out its filament of silk behind it. It reaches the circumference, takes its four paces along the founda- 94 A NATURALIST IN HIMALAYA tion-line, halts and anchors its filament. In this way a radius of one strand is secured. But this is not sufficient for the spider. The line must be of double strength. The spider sets about it in this way. It climbs back again to the centre of the snare, but this time it makes its journey along the new radius that it has just laid down. It pays out its filament of silk behind it. It reaches the centre, draws tight, anchors and secures its line. In this way the radius is duplicated, and this gives additional strength to the essential framework of the snare. I pass to the next stage of the architecture. The radii are complete. In the snare I have just examined they are twenty-four in number. The spider now commences the next feature of its work. It winds five turns of a slender filament around and close to the centre, anchoring it at every spoke. Thus it con- structs its hub. It does not always complete its radii before commencing the hub. It may lay down a few radii, then take a turn on the hub, then again resume the radii. No doubt the hub helps to secure the radii. But its construction has a greater value ; for, as the spider circles five times round the centre testing each radius in succession at every circle, it satisfies itself repeatedly that all its radii are in place. It examines with its dividers the position of each pair of radii, and if they are not in accurate position it proceeds to remedy the defect. An experiment will make this clear. A snare is under construction. All the radii are in place. The spider is engaged in the winding of its hub. I divide one radius. The spider circles round and reaches the gap made by the lost radius. It is GEOMETRICAL SPIDERS 95 obvious that it is feeling with its leg for the radius, but finds nothing in its place. !t recognizes the loss, ceases its work on the hub, runs out a new radius and again resumes the spinning of the hub. The experi- ment is repeated and more radii are divided. But the spider replaces the lost lines so long as it is engaged on the hub. It is thus clear that the time of hub- formation is the time for testing a previous stage in the construction ; the time to examine if every radius is secure. This process of testing the radii is one of great importance, for the absence of a radius means a loss of symmetry in the web. Thus the spider is most dili- gent in this stage of its duty. I will mention an experi- ment to indicate its persistence in this important task. A snare of twenty-four radii was being reconstructed. The old snare had been battered to fraofments ; and the spider, having cleared the remnants, was building a new structure in its place. It was laying out its radii. Now as fast as the spider secured a radius, I severed one that it had previously laid down. As the spider worked on one side, I divided on the other side. My destruction kept pace with its con- struction of the radii. The spider continually found the gap that I had made, a vacant interval where there should have been a radius. But it was equal to the emergency. It ran out a new radius. As fast as the spider discovered the injury it remedied the defect. In all I divided a radius twenty-five times and the spider constructed new ones in their place. Sometimes the same radius was severed three or four times, and each time the structure was replaced. After the twenty-five divisions the spider refused to 96 A NATURAIJST IN HIMALAYA construct any more radii. The snare had eighteen in position, and the spider, satisfied with this, passed on to the next stage of its work. Such is the persistence of the spider in the appHcation of its radii. In this snare that should have contained twenty-four radii, the spider constructed eighteen together with the twenty-five that I had severed. In all it laid down forty-three instead of the normal twenty-four. From this experiment we rest satisfied as to the mechanism by which the spider tests its radii, and we see the clear determination of the litde architect to make every radius secure. Such are the geometrical means by which the spider constructs its radii. I pass now to consider if similar methods are employed in the other features of its work. The radii and hub are complete and the next step in the architecture is the construction of the temporary spiral. This binds the radii together. It is the scaffolding of the snare. We again watch the workmanship. We again discover the method of measurement ; the mathemati- cal instinct on which the accuracy of the work depends. Round goes the spider from radius to radius construct- ing the first turn of its temporary spiral. Watch it carefully at one radius. Its fore limb is applied to the hub ; its spinnerets touch the radius and a definite length is measured off along the radius ; the length being the distance from the tip of the fore leg to the spinnerets. Where the spinnerets meet the radius a line is secured. The spider passes on to the next radius. The same process occurs. The same length is measured off on this radius. The fore limb again finds the hub, the spinnerets again touch the radius GEOMETRICAL SPIDERS 97 a similar distance away. The line is drawn tight between the radii and secured. So continues the spider on to the next radius and completely round the snare. At every radius the same distance is measured ; the distance being the full expanse of the spider's body from the tip of its fore leg on the hub to the spinnerets applied to the radius. The first turn is complete. The spider passes on to the second turn. The same mechanism follows. But the spider measures its distance not from the hub but from the first turn. And as the second turn is measured from the first turn, so also is the third turn measured from the second turn, and the same mechan- ism continues round the snare until all the turns are complete. Again we find that the method of construction is a simple geometrical act. The spider is faced with a definite problem and must solve it on mathematical lines. Each turn in the spiral must be parallel, and only by accurate measurement can this parallelism be secured. The spider by its wonderful instinct can meet the problem. It has many organs of measure- ment at its command. In fashioning its temporary spiral it employs the simplest of all — the measurement of its own length. The temporary spiral is complete. A solid frame- work is in position to receive the viscid spiral, the deadly element of the snare. No part of the fabric is more beautiful than this, nor displays its mathematical perfection to so remarkable a degree. The question is, how is all this accuracy attained ; how does the spider measure with such precision this most wonderful portion of its architecture ? H 98 A NATURALIST IN IIIIMALAYA Again wc watch the spider at work. It has sealed the end of its temporary spiral and immediately starts at the first turn of its viscid spiral. Out along a radius it travels with agile movements and unerring skill. It takes three hurried paces, halts, applies its spinnerets to the radius and secures a line. The first turn of the viscid spiral has commenced. Back along a radius it hastens and across the last turn of the temporary spiral that now serves it as a bridge. It reaches the next radius and hurries out along it. We watch carefully, for this is the important point. It moves out along this radius for exactly three paces. It halts, applies its spinnerets, draws tight and secures the line. Back again along the radius, over the next bridge, out along the next radius for three paces, and it again secures the line. And so on for every radius till the first turn of the viscid spiral is complete. Every attachment in this turn is fixed to every radius exactly three paces distant from the last turn of the temporary spiral. Again do we find that accuracy of measurement is the clue to the spider's work. As the turns of the temporary spiral are measured, each one from the preceding turn, so is the first turn of the viscid spiral measured from the last turn of the temporary spiral. Similar is the principle but different is the method. The interval between each turn of the temporary spiral is short ; it can be measured by the body-length. The viscid spiral is laid down at a greater distance ; it must be measured by the number of paces, an equal number at every spoke. Thus does the geometrical spider measure and calculate each step in its architec- ture. How human-like are these simple acts, all the GEOMETRICAL SPIDERS 99 more wonderful because they are simple. For as the spicier paces the distance through its snare, so does man often, in his daily life, pace his distance over the ground. The first turn of the viscid spiral being complete, I come now to the construction of the succeeding turns of that spiral, the perfect parallelism of which makes for the beauty and subtlety of the snare. How is this parallelism secured ? How is each filament in the spiral adjusted by the spider at an equal distance from each adjoining filament ? We have seen that the second, third, fourth and succeeding turns of the temporary spiral are measured off each from the pre- ceding turn. We have also seen that the first turn of the viscid spiral is measured off from the last turn of the temporary spiral. In fact the distance of each turn is estimated from the turn immediately internal to it. I therefore first thought that the spider in some way measured all the turns of its viscid spiral from the bridge formed by the temporary spiral. I was unable to understand how It could effect this, until at last a simple experiment convinced me that I was mistaken ; that the temporary spiral was not the guide to measure- ment, but that the architect worked on some different plan. I found a spider spinning. The viscid spiral was being laid down. Between every attachment the spider had to cross over its bridge formed by the temporary spiral. With a sharp pair of scissors I divided the bridge in one segment. The spider took no notice and circled on. In every other segment It pursued its normal course, crossing over the customary bridge. But In the experimental segment the bridge was gone and the spider had to continue Inwards until 100 A NATURALIST IN HIiVIALAYA it reached the next turn of the temporary spiral before it could cross over. This did not alter the accuracy of the spider's work. Without any hesitation it made use of the inner bridge, and I was surprised to see that this did not in any way interfere with the parallelism of the viscid spiral which it was laying down. If, as I imagined, the spider measured each turn of the viscid spiral from the last turn of the temporary spiral, then in that sei^ment where the turn was divided the parallelism should have been lost, for the point of measurement was gone. But this was not the case. The threads were as parallel in the experimental segment as in any other segment. We must look to some other mode of measurement to explain the secret of the work. It is clear that the measurement is not made from within. Perhaps it is made from without. The spider may measure the turn of its viscid spiral from the turn that lies just external to it and which was laid down in its last circuit. We watch the operation with the greatest care. Out along the radius moves the spider until it reaches the point where it will attach its thread. A peculiar motion now occurs and this is the secret of its work. The attachment is not yet made. The whole body of the spider first undergoes a partial rotation ; the fore limb is extended forward ; the sensitive tip gently touches the filament of the viscid spiral laid down in the previous circuit, and, when this is done, the spinnerets are applied to the radius and the attachment is made. What is the spider doing? Surely it is using its fore limb to measure the correct distance from the previous turn of the spiral at which to make its new attachment. GEOMETRICAL SPIDERS 101 Just as a human being, when drawing one Hne parallel to another line, uses the position of the first line to judge with his eye the accuracy of the second line, so does the spider in weaving the beautiful parallel texture of its snare use the position of one turn of its spiral from which to measure with its fore leg the accurate position of the next turn. Observation of the spider at its work makes us almost confident of the truth of this. But its move- ments are so agile ; the turn of its body, the gentle touch with the fore leg, the rapid application of the spinnerets, follow one another so quickly that it is difficult to be certain of the sequence of events. If the fore leg is indeed the vital organ in the operation, the measuring rule by which one line is laid parallel to the preceding line, then a few careful experiments should confirm the truth of the belief. If the spider places one turn in position by estimat- ing the distance from the preceding turn, then if I divide the preceding turn, the spider will have lost its point of measurement and parallelism will be destroyed. I choose one segment for the experiment when the spider is working at its viscid spiral. It has just crossed the segment, leaving a filament in its train. I divide the filament. The spider circles on, laying down the spiral to perfection until it again reaches the experimental segment. Arriving at this segment, what happens ? The spider as usual stretches forth its leg to feel for the line laid down in its last circle. But the line is gone. The spider finds nothing there. It stretches still further forward and feels the next line, the one laid down in its second last circle. This line it takes to be the true line. From it the measure- 102 A NATURALIST IN HIMALAYA ment is made, and the filament anchored in the wrong place. The diagram (Fig. 3) illustrates what has occurred. Turn first to diagram a. Let w,x,y, z be four adjoining segments. Let x be the experimental segment, and let three turns, i, 2, 3, of the viscid spiral be complete. I divide the innermost turn in segment x. Now turn to diagram b. The spider circles on laying down the fourth turn of its spiral all round the snare. At length it reaches the radius a Fig. 3.— Loss of parallelism resulting from division of one turn of viscid spiral in one segment. (a) Viscid S]nral divided in segment X. (J)) Result of spider's work. Loss of parailelisin in both X and Y. Arrow marks the direction of spider's circle. between z and y. Here all is well. It feels in its measurement the turn it has last laid down and the fourth line is parallel across segment z. It passes on to the radius between x and jj/. It reaches forward to feel line 3. But line 3 is gone, so it must touch line 2. Its measurement is incorrect. The attachment is made in the wrong place, farther out on the radius, and the line drawn across segment y is out of parallel. The spider passes on. It reaches the radius between w and X. Stretching forward, it touches the correct line. It anchors its filament in the right place. But the GEOMETRICAL SPIDERS 103 other end of that filament has found a wrong attach- ment, therefore the Hne across secfment x is also out of parallel. To sum up, the result of the experiment is this. One turn of the viscid spiral is divided in one segment. Parallelism is lost in both that and the pre- ceding segment. In the one the lines diverge, in the other they converge. The essential fact is that, the point of measurement being removed, then the parallelism is lost. Fig. 4. — Loss of parallelism resulting from division of one turn of viscid spiral in two segments. {a) Viscid spiral divided in segments X and Y. {b) Result of spider's work. Loss of parallelism in both X and Z. Arrow marks the direction of spider's circle. I perform a similar experiment, but divide the spiral in two adjoining segments (Fig. 4, a and b). I will not labour over the details, as these the diagram should explain. Again a similar sequence follows. The spider measures from the wrong lines ; the attachments are made in the wrong place, and the perfect parallelism is lost. Difficulties may prevent the success of these experi- ments. For when I divide a filament, little tags of the spiral are left attached to the radii. Now the spider in reaching forward to find its point of measure- 104 A NATURALIST IN HIMALAYA ment may touch one of these httle tags and, beHcving it to be the spiral, may anchor its new filament correctly. Moreover, the experiment seldom succeeds when the spider is working at the inner and smaller turns of the spiral. This, I think, is due to the fact that here the spider can move directly across from radius to radius without deviating its course, or can stretch directly to its point of attachment from its bridge on the tempo- rary spiral, so that the previous turn of the viscid spiral is here much less important as a means of measurement than in the earlier and more external part of its construction. But these difficulties avoided, we reach a clear conclusion. Each turn in the viscid spiral is the essential guide to the accuracy of the next turn. For if the one be divided then the next is incorrect. And from the way the spider feels with its leg at each attachment, there is strong reason to think that the fore leg is the organ on which the accuracy depends. These experiments strengthened my belief that the fore leg was the instrument employed by the spider to draw line parallel to line. But a third experiment overcame all doubts. I found a snare in which the spider had cot leted the outermost turn of the viscid spiral. VVith a fine pair of scissors I succeeded in cutting off the tips of the spider's two fore legs. By this operation I had removed what I believed to be the sensitive organs of measurement, and I was eager to detect whether the spider could continue the construction of the snare after so serious a mutilation, and, above all, if it could still ensure the parallelism of its lines. Immediately after I had nipped off the tip of the GEOMETRICAL SPIDERS 105 limbs, the spider hurried away along the foundation- Hnes to a place of shelter outside the snare. After a lapse of fifteen minutes the spider again returned, remained motionless for about two minutes at the centre of the snare, and then moved out along a radius to continue the work of construction. It was distinctly- evident that the movements of the spider were greatly hampered by the mutilation. It advanced slowly, deliberately and more laboriously than before. There was a complete absence of all skill and agility in its motion. It approached the point where the work had been interrupted and again took up the thread of its labour. Away it started on its spiral round, strug- gling with difficulty from radius to radius and trying in vain to attach a spiral at equidistant radial points. There was no mistaking the fact that the spider was at a great disadvantage after the loss of its organs of measurement, and that it was quite unable to ensure the parallelism of its lines. It attempted to use its amputated stump, waving it helplessly in the air, but its efforts were in vain. Yet the spider was more adaptable than I thought. Finding itself unable to measure after the loss of its fore limbs, it began now to try and estimate the distance by the use of its hind limbs. In this way a limited degree of compensation took place. It made some attempt at measurement, but with indifferent success. Yet the spider circled on. Laboriously it plodded round and round the snare, continually measuring its distance incorrectly and making the adhesions in the wrong place. Three times it neglected to insert a whole spiral ; again and again it made attachment to the spiral instead of to the radius, and sometimes it passed by a radius with- 10(5 A NATURALIST IN HIMALAYA out nicikinf^ any attachment at all. Yet the spider toiled deliberately on. Smaller and smaller grew the spiral, stranger and stranger grew the irregularities of its structure, yet the spider, in spite of all its difficulties and mutilations, brought the snare to a completion. But it was of a remarkable workmanship. No one who has contemplated the mathematical accuracy of a circular snare could have looked with indifference on its tangled texture. Its radial and parallel beauty was lost ; threads in confusion adhered to one another ; triangles, quadrilaterals of every shape replaced the perfect symmetry of its parallelograms ; spirals crossed other spirals ; broad and narrow spaces lay indifferently between the turns ; radii were drawn out of shape or were left without attachment ; the web was not a visible harmony but a strange intermingling of confusion and disorder. No experiment convinced me so strongly that the fore limbs were the all-important organs of measure- ment to ensure the perfect symmetry of the snare. Such are the geometrical powers of the Epcira ; wonderful in their origin, simple in their execution, accurate in their result. Measurement and precision are the secrets of the work. On the possession of these powers, and the instinct to employ them, depend the perfection and beauty of the snare. On its body it carries its organs of measurement — the number of its paces, the length of its body, the divergence of its limbs ; the very same organs that, in his rough measure- ments, primitive man might use. Employing those organs with mathematical precision, it weaves that silken texture, every line in harmony making the whole so exquisite in our eyes. Yet underlying the complex GEOMETRICAL SPIDERS 107 structure is a pure and simple mechanism conducted on rigid lines. Let us not think less of the beauty of the architecture because it is built on the strictest measurements, nor less of our wonder at the architect because it is governed by unswerving laws. CHAPTER VII FURTHER OBSERVATIONS ON THE GEOMETRICAL SNARE Ultimate fate of temporary spiral — Reversal of spiral — Reason of reversal of spiral — Example of plasticity of instinct — Spidei-'s power to esti- mate tension — Delicacy of sense of touch — Industry of Artwcus — Mode of emission of filament — Economy of spider and destruction of snare — Perfection and imperfection in snare. In the previous chapter I have endeavoured to make clear the mathematical powers by which I believe the spider works, and I now pass to consider some other features of interest in the geometry of the circular snare. I must first mention one incident in the workmanship of the spider, since it serves to illustrate how a certain step in the architecture can serve merely as a temporary support until the next step is complete. I refer to the ultimate disappearance of the temporary spiral. If the viscid spiral was brought to a completion while the temporary spiral still remained in place, then the final workmanship would consist of a mixture of two spirals, one of viscid and the other of non-viscid lines. But so clumsy an architecture will not suit the spider. It works on a more perfect plan. Its edifice must contain only a single spiral composed solely of viscid lines. How does it effect this.'* We watch the spider at its work. In the snare under observation the temporary spiral is complete, and we notice that the spider has just sufficient room 108 THE GEOMETRICAL SNARE 109 to fit in four turns of the viscid spiral between the circumference of the snare and the outer turn of the temporary spiral. What I wish to make clear is this : that after the spider commences on its viscid spiral it will have sufficient space to complete the first four turns, but that the fifth turn will happen to meet the outer turn of the temporary spiral and the two will become intermingled. We watch to see what the spider will do. It completes the first three turns in the ordinary way, of course using the outer turn of the temporary spiral as the bridge to pass across from radius to radius. It comes to the fourth turn. It has sufficient room to insert this. It is the next turn that will coincide with the temporary spiral. What does the spider do ? It rises to the emergency. It behaves as though it foresaw its difficulties. It sets about destroying its bridges so as to allow a free space for the fifth turn of its viscid spiral. Each time it completes the fourth turn of the viscid spiral in any segment it at the same moment severs the bridge in that segment. It first crosses the bridge, then divides the line behind it. And this process of division con- tinues until the outer turn of the temporary spiral has been severed all round the snare. The fifth turn of the viscid spiral can then be freely laid down. A similar destruction follows in the case of the inner turns of the temporary spiral. As soon as the spider finds that the next turn of its viscid spiral will get entangled with its bridge it adopts the ingenious method of simply dividing the bridge. Each turn is severed as soon as the viscid spiral reaches it. Thus does the temporary spiral disappear. It has served its purpose and has served it well. It has 110 A NATURALIST IN HIMALAYA served as a measurlno^ line from which to adjust the outermost turn of the viscid spiral, it has bound the radii together until the viscid spiral was in place, it has served as a succession of many bridges to convey the spider from radius to radius. All these functions arc now complete ; they take no part in the ensnaring- of the prey. The temporary spiral is there- fore of no further use ; its presence any longer would ¥lC. 5. • Diagram of reversal of spiral. (a) One method. (/*) Another method. The spider has reversed at the point X. lead to loss of symmetry and to imperfection ; it is therefore destroyed and disappears. I come now to consider another feature in the architecture of the snare. If an Aranens be carefully watched while constructing its viscid spiral, it will be noticed that from time to time the spider stops, turns about and commences to circle again round the snare in the opposite direction. It rarely completes its spiral from the first to the last turn by always circling in the same direction. It is working to the right. It suddenly halts, seals off the end of its spiral, turns about, commences a new spiral and starts off on a THE GEOMETRICAL SNARE 111 fresh circle to the left. I shall speak of this change in the mode of operation as " the reversal of the spiral." A reference to Fio-. 5 will show two modi- fications of the way in which this reversal is made. For a long- time I was at a loss to understand why the spider should suddenly, and without apparent cause, interrupt its instinctive circle and start a reverse Fig. 6. — Reversal of spiral in an eccentric snare. Points of reversal marked with an asterisk. Twelve turns on narrow side, twenty tui ns on broad side of centre. spiral in the opposite direction round the snare. It always occurred so unexpectedly and seemed such a very unessential act. It was so complete a change in the undeviating course of instinct, and instinct moves by inexorable laws. I noted, however, after examining a number of snares, that what I have called the centre was seldom a true mathematical centre. The radii varied in length, and the centre from where they all diverged 112 A NATURALIST IN HIMALAYA was frequently very eccentric. Thus the spider, when constructinq^ an eccentric snare, would have to separate the various turns of the viscid spiral more widely on the broad side of the centre and approximate them on the narrow side, or else would have to insert more turns on the former than on the latter side if it wished to produce a harmonious fabric. Now every time the spider turned in its course it inserted, as is clear from the diagram (Fig. 6), an additional filament on that side of the centre, which addition was absent from the opposite side. Can it be that, in order to ensure harmony in its snare, the spider reverses on the broad side and continues an uninterrupted course in its work on the narrow side.'* Certainly this method would produce symmetry, and in all probability would be a more simple operation for the spider than the attempt to draw parallel lines at different distances, wide apart on the broad side and closer together on the narrow side of the centre. I discovered a very eccentric snare with the radii just completed. I followed the spider at its work on the viscid spiral. I carefully noted the number of reverses and whether they occurred on the broad or narrow side of the centre. The spider circled round and round the snare and made exactly thirty complete turns from its commencement to its com- pletion. But in addition to the complete turns, the spider reversed fourteen times, and every single one of those reverses added an additional filament to the broad side of the centre and not one to the narrow side. The turns of the spiral on the broad side were not more widely separated than those on the narrow side, but their number was much greater. After the THE GEOMETRICAL SNARE 113 completion of the snare there were forty-four turns on the broad side and only thirty on the narrow side. It was evident that the cause of the reversal of the spiral was the eccentricity of the snare, and that it was the means adopted by the spider to perform the difficult operation of winding spirals round an eccentric point with the least possible loss of parallelism and symmetry. This reversal of the spiral is to my mind an excellent example of the plasticity of instinct. No two snares can be exactly alike ; some are more, others are less eccentric. All must vary somewhat in their construc- tion. In some the number of reversals are few, in others many, possibly in others there may be none required. In some the reversed spiral may be so short as to connect but two radii, in others it may connect ten. In every snare the reverses must vary in number, in order and in length. What a wonderful flexibility of instinct must a spider possess to adapt its work to such changing circumstances and construct in the end a perfect architecture. Every snare the spider weaves must differ in some way from its predecessor and must demand some modification in the plastic instinct which may never before have been called into action. It would not be surprising to see every snare varying in length or breadth or even in the number of the turns of the spiral, for such variations are those of the ordinary course of nature and directed to no vital end. But it is wonderful to think that this varia- tion in the reversal of the spiral is so necessary, so intricate, so universal, and is directed to the ultimate purpose of mathematical perfection in the complexity of the snare. It is indeed strange to witness the 114 A NATURALIST IN HIMALAYA mechanical motion of the spider round and round the web and to ponder over the heedless instinct that compels the same eternal round. But still more strange would be the picture of the snare if instinct was so blind as to allow of no reversal and to compel the spider in the same headloncr course. The whole fabric would be unsymmetrical, all its perfect beauty would be lost. The astonishment is not in seeing the monotonous routine of instinct, but rather in seeing that instinct so plastic as to enable the spider to achieve this perfect symmetry no matter how great is the eccentricity of its snare. Is it possible to gain any clue as to what guides the spider in the performance of this essential act? How does the spider know when to reverse and when to pursue an unbroken course ? I cannot with complete confidence explain this, but I strongly suspect that it is guided by its fine sense of touch and the power to estimate the tension of its lines. I have observed that a small species of Epeira, which constructs its snare in the coniferous forests, seems distinctly to possess the power of discriminating between any alterations of tension that may exist at different parts of the snare. This spider weaves its web at the point of radiation of three foundation-lines. If one of these foundation-lines be gently stretched away from the snare, the spider, while resting at the centre, will immediately recognize the change in tension that has occurred. It will form a correct impression of the direction of the abnormal strain, and will advance to investigate the cause of the disturbance. I am satisfied that the Epeira can discriminate between different states of tension, and we should remember THE GEOMETRICAL SNARE 115 how acute is the delicate sense of touch. Watch a spider seated at the centre of its snare. Its sensitive limbs diverge so as to rest on radii coming from all parts of the circumference. It can in this way detect vibrations in all directions, as it is in tactile com- munication with every area of the snare. It is interesting to see the spider testing the radii at every thrill and feeling their tension when it is doubtful of its capture. I have thought that the stimulus to produce that wonderful accuracy in the reversal of the spiral might be the differences in tension along the unequal radii of the eccentric snare. For since a spider is able to estimate changes in tension, it is probable that it could also differentiate between the long and short radii of an eccentric snare, which would certainly, if they were wires or strings, give to the human fingers very per- ceptible differences in sensation. By the difference in tension the spider should discriminate between a radius on the broad side and a radius on the narrow side of the centre. At the moment of attachment of the spiral to a radius the spider probably estimates the length of free radius between the point of attachment and the centre of the snare ; and in an eccentric snare all these lengths will vary. The sensation produced by contact with long radii would be of a different nature to that produced by the short radii, and the spider may react to the former stimulus by a reverse. The outer por- tions of the radii, to which the previous turns of the spiral have already been attached, would not be con- sidered by the spider, as that portion would be damped by the turns of the spiral in the same way as the finger damps off a segment of a violin string. 110 A NATURALIST IN HIMALAYA Hius a spider, during the construction of a circular eccentric snare, may, by its exquisite sense of touch, differentiate between the long and the short radii. It may continue to reverse its spiral so as to attach addi- tional turns to the lon^r radii until sufficient reverses have been made to give the free parts of all the radii an equal length and convey a uniform stimulus to the sense of touch. This speculation is to a great extent surmise. It is supported by the fact that the reversals are more numerous durin"" the earlier turns of the spiral when the inequality of the radii would be more easily felt. In the latter half of the construction the number of the reversals is few or there may be none at all. And this I think is due to the fact that the radii are then less unequal owing to the many reversals already made. And if this view be true, then how delicate must be the sense of a spider's touch. It must be developed to so high a degree of perfection that the mathematical accuracy of the work will very largely depend on the delicacy of the tactile power to estimate the changes of tension in the lines of different lenoth that radiate from the centre of an eccentric snare. A geometrical spider engaged in architecture pur- sues its work with a restless energy. The bees, when seeking nectar from the flowers; the ants, when storing up provision in their nest, are no more tireless in their toil. It moves with hurried pace along every spoke ; it measures its lines with almost imperceptible touch ; it seals its filament in an instant and then hastens away. All its movements are so agile that at the moment it can have but one object in view, the speedy completion of its snare. THE GEOMETRICAL SNARE 117 I made some attempt to investigate the industry of the architect ; to estimate the amount of work per- formed and the time taken to complete it. Spanning a deep reflecting pool I found the fragments of a snare. Only the external frame, composed of strong founda- tion-lines, remained. The more fragile texture in the centre had vanished. It was evening. Soon the Epeb'a would descend to its ruin, for the time of work was drawing near. I thought I would wait for the reconstruction to commence and attempt to estimate the length of line emitted and the distance travelled by the spider during the complete construction of its snare. I waded out into the pool, found the diameter of the framework to measure twenty-two inches, and awaited the commencement of the work. As the sun sank low in the sky, the Epeira felt the call to work. It moved out along the foundation-lines, first to explore the framework, then to extend the radii through the snare. I followed all the movements of the spider from its first attachment to the completion of the web, but I did not take the foundation-lines into my reckoning, as these were a permanent structure laid down many days before. With the exception of these main foundation-lines, I estimated that, from the commencement to the completion of the snare, the spider emitted 122 feet of filament, made 699 attach- ments and travelled over a distance of 178 feet. Yet the whole was woven into a circular web 22 inches in diameter and occupied the spider only 36 minutes. This seemed to me an excellent instance of untirino- industry as displayed by the more humble of organic beings. It has been a subject of discussion how the silken 118 A NATURALIST IN HIMALAYA filament escapes from the spider's spinnerets. Is it drawn out by external traction or is it emitted by the muscular effort of the spider ? I am inclined to believe that the spider has no power to shoot forth its own fragile thread. If we look to that large spider, the Argyope, wc see that the viscid spiral escapes from the spinnerets only with great difficulty. The Argyope certainly cannot shoot forth its viscid spiral. A defi- nite traction is necessary to withdraw it. For once this spider arrives at the construction of its viscid spiral, its movements become more laboured ; it cannot circle with the rapidity of other geometrical spiders. At each attachment of the viscid spiral it has to grasp the adhesive filament with its tarsus, slowly draw the sticky line from its own spinnerets, sometimes transfer it to the opposite tarsus to gain an additional purchase, and not until it has with no little labour pulled from its own abdomen a sufficient length of line is it able to attach the spiral. Like the Argyope, so I think are the rest of the Epeiridce, unable by their own internal force to thrust out their silken lines. The thread must feel a crentle strain before it can be drawn from the spinning-wheel. I do not know of any time during the emission of the silk when this strain is not clearly present. As the spider circles from spoke to spoke it strains on its last attachment ; as it suddenly drops suspended on a fila- ment the strain becomes its own weight ; as it gives its first line to the breeze the strain is on the tuft of finest fibrils that catch the moving air ; and in the beautiful Argyope the strain is often the traction exerted on the line by the spider's own legs. During the emission of the line, therefore, there is always some tension pro- THE GEOMETRICAL SNARE 119 duced by an external strain. Never does a flaccid filament hang loosely from the spinnerets. May not the tension which is ever present be present of necessity ? I have dwelt so long on the method of construction that I will say but little on the destruction of the snare. Yet nothing in the architecture of the spider so sur- prised me as the manner in which it disappears. I first observed the process in a true home of the Epeirida:. Where the water falls down over a ledge of rock and splashes in a transparent pool the spiders love to construct their snares. Amidst the noise of the falling waters the smaller flies revel in the cascade. Above the pool they hover and dash at intervals amongst the dancing drops that leap from the quiver- ing pool high into the air. It is strange that they should choose the commotion of the waters. It may be for pure pleasure that they dart through the glitter- ing drops and flash over the tiny foam. Where the flies hover, there the spider will weave its snare. At the very edge of the fall the slender lines extend, and look as though they would be torn to pieces in the spray. But the silken threads are strong, and, as the sparkling drops ascend, each line in the slender fabric is spangled with a row of pearls. I often visited this pool at sunset to watch the colony at work. The snares were then renewed. After twenty- four hours only the tattered fragments remain ; a new snare was spun every evening. One evening on coming to the pool, I happened to look on a tattered snare with the spider resting at the centre. The snare must have done duty for twenty-four hours ; it was very much broken, and attached to its meshes were 120 A NATURALIST IN HIMALAYA hundreds of tiny insects too minute to attract the attention of the spider at the time of their entangle- ment. As I contemplated the ruin of the snare, the spider slowly emerged from its position at the centre. It advanced along one of the radii, and it was imme- diately evident that it was breaking up the snare in its progress. Closer observation revealed the extraordi- nary fact that it was actually eating up its own snare. As it proceeded outwards the spider swallowed the radius, the lines of the viscid spiral, all the little tags of broken filaments and the innumerable tiny insects that lay entangled in its course. On reaching the outer extremity of the radius, the spider returned to the centre and rested there for about five minutes. It then commenced to destroy and devour a second radius with its viscid attachments and again rested at the centre. This continued until all the radii, the whole of the spiral and the hundreds of little insects had all been devoured. After the destruction of each radius the spider always rested at the centre for some five minutes, presumably for the purpose of emptying its stomach so as to fit it for receiving the next radius. The spider did not devour the foundation-lines of the snare, as it intended to use them for the main frame- work of the new snare. However, it carefully examined these lines and removed from them any loose filaments or minute insects that happened to remain attached. What wonderful economy is this to allow nothing to disappear! If in a snare I divide a number of fila- ments, the spider will often come out and swallow eagerly the little tags of silk wherever it finds them. But in this final act how much more strict is the economy displayed ! The construction of the snare THE GEOMETRICAL SNARE 121 expends the spider's substance ; but all that remains, the tattered lines, the tiny insects, again return to the architect ; even the foundation-lines are searched that nothing goes waste. I was at first very much surprised to think that a spider's stomach could be so capacious as to contain the complete snare. In this, however, I was much mistaken ; for I found that a large, complete snare, eleven inches in diameter, was of such delicate sub- stance and compressible into so small a bulk that when rolled into a ball between the fingers, it formed a compact mass but little larger than an ordinary pin- head. A spider will often swallow entire a fly of much greater dimensions than its own compact snare. I look on the circular snare of the Epeira as almost as beautiful an example of mathematical accuracy in the life of organic beings as the exquisite structure of the honeycomb. But how much more wonderful does it all seem when we picture the web as a potential fabric, first woven into an inimitable harmony to lure to death thousands of living creatures, then, tattered and torn in the tragedy, to be again received into the maw of its voracious host, to be repurified in the strange economy of a spider's structure, to emerge again from the spinning-wheel in fine transparent filaments, to be woven again into the same lovely texture, and to repeat day after day the same eternal drama that fills the mind with such enthusiasm and admiration. Throughout this chapter I have spoken repeatedly of the perfection of the snare. And this is true in a general sense. But 3. closQ observation of nature 122 A NATURALIST IN HIIMALAYA shows us that in the ortranic world there is nothing really perfect. Even in the structure of the human eye there is error upon error. So it is with the snare. Exquisite as is its workmanship, it is not in the strictest sense geometrically exact. Careful observa- tion will detect numerous imperfections. The centre is often not a true centre, the radii diverge from an eccentric point ; the radii, first thought to be of equal length, are found to be unequal ; the angles, though approximating closely, all slightly differ ; lines, though in apparent parallel, would many of them soon meet. The vision of the whole is one of delicate perfection ; the inspection of the detail reveals minute imperfec- tions. But surely this does not diminish our wonder at the workmanship. It is enlightening to see the apparently accurate built up of countless error. And the errors are trivial. Each, no doubt, has some reason for its existence ; though each to our eyes appears a fault, yet they all blend in harmony. So it is all through organic life. Everywhere in nature, both in instinct and in structure, we witness imper- fection and error. Even that most wonderful and economical of instincts, the cell-building of the honey- bee, is far from really perfect. I doubt if in the whole world of nature there exists a faultless instinct or a perfect structure. But few structures can better claim perfection than this delicate circular snare. Such is the construction, such the destruction of a spider's geometrical snare. This is the architecture of the Araneus, though I do not speak for the rest of the Epeiridcs. Strict and unswerving mechanism is the secret of the work, not only of its accuracy but of its beauty. The power to nieasure is the guiding THE GEOMETRICAL SNARE 123 instinct that underlies the mechanical routine. The spider is to my mind the more wonderful because it is mechanical, because it works on the strictest plan. With instincts so perfect it fashions its lovely fabric. I know not which to admire in it the more, the geometrical instinct that builds it up, or the economy that tears it down. CHAPTER VIII THE INSTINCT OF SPIDERS Spiders and weather — Force of instinct — Repair of web -Experiments to indicate the unswerving force of instinct — Slavery to instinct — Transference to other snares— Spider not entangled in its own snare— Mode of escape — Protective resemblance — Special senses of spiders. The days are dark and dull. Heavy threatening clouds rest on the encircling hills. A black mass of nimbus hangs over half the sky, enshrouding the mountains at its base, and high in the zenith breaking into grey ragged fragments that seem to tell of the fury behind. Low peals of thunder issue forth and lightning flickers through the gloom. The sun is setting, and its rays streaming across the sky penetrate the dark cloud. A bow of intense brilliancy appears through the threatening vapour with every hue de- fined. Without is a second and fainter arch reflecting in inverse order the clearer colours of the brighter bow. Above they fade into the lowering sky ; beneath they shine firm against the higher hills that glow with i. dull purple. There is little need to visit the spiders on such an evening as this. Few will be at work. For the Arancus understands the sio^ns of the weather. It will not spin when rain threatens. It knows that the falling drops would annihilate its work. To find the Arancus in full vigour we choos(^ a dry 124 < < a X O H < W HI a a H ^ T -■** ■ I a THE INSTINCT OF SPIDERS 125 September evening as the sun sinks in a clear and settled sky. A few snow-white (locculi of cloud rest lightly on the wooded hills ; a gentle haze of dust dims the further peaks, and all the valleys are re- fulgent with the evening light. When the sun dips behind the enclosing ridge the spiders are most busy at their work. They toil while the hills and clouds change their hue beneath the fast declining light. The green woods turn to a dull purple, the white clouds pass into a faint pink or, tinged with yellow, they assume a golden hue. On such an evening each spider is busy ; all are weaving with a subtle skill. Filaments of inimitable texture are being wafted over the rippling stream ; ingenious nets are being spun amidst permanent foundation-lines, and snare is being linked to snare. The intricate sheet of web soon spans the channel in the hill. There is no strife ; all work in perfect harmony. By sunset the fabric is woven. Each little architect takes its station at the centre of its web and there awaits the entanglement of its prey. Not till another sunset will work agrain commence. In the meantime insects innumerable will be captured ; the juice will be sucked from their bodies, and the spider will feed in peace and plenty. I have dwelt so long- on the mechanism of con- struction, that I will now say something of the motive instinct on which all this work depends. At first sight the work of the spider looks like the act of an intelligent being. How exquisite is all its harmony ! The precision of science here blends with the beauty of art. Untiring industry, exact method, faultless accuracy, inimitable skill raise this edifice 126 A NATURALIST IN HIMALAYA of mathematical beauty. It mi^ht be a work of profound wisdom ; the product of a calculating mind measuring angles, estimating areas, tracing with skill the geometrical curve, examining tensions, appreci- ating minute imperfections, halting, reversing, circling backward as perfection may require. Is this pre- meditated design ? Are spirals, parallels, angles, areas, clearly depicted in this creature's mind to make her so cunning and so exact an architect ? Does she fashion the beautiful because she loves beauty, the accurate because she loves precision ? I cannot think so, I believe the spider lives in total ignorance. She knows naught of her wondrous work. Its beauty and precision are both lost on her. Why or how it is made she cares not. She is as oblivious of her spiral filament as is an ammonite of its spiral shell. What in our ignorance we call instinct, impels her to her task. She must work ; she knows not why, she knows not how. The delicacy of her silken threads, the perfection of her workmanship, gratify other minds than hers. Certain acts on the part of the spider will help us to appreciate this. First of all, can the spider repair its web? If so, then it can claim the gift of intelligence. For to repair an injury the spider must appreciate the nature of the damage, and direct its action to a definite premeditated end. One evening I deliberately injure a snare. I excise a portion of three adjoining radii with six turns of the viscid spiral. The sides of the rent are drawn apart by the elasticity of the web, and a hole remains through which three or four fingers can be passed. The spider, after a momentary alarm, takes no further notice. It patiently awaits its prey. THE INSTINCT OF SPIDERS 127 No attempt at repair is made this evening. I visit the snare the following morning. The spicier is still at the centre ; a number of insects are strung along the filaments, but the rent still remains. Indeed it is enlarged, for the snare is here weakened and gives way further before the strain. The fact remains that there is no attempt to repair the damage. This a spider cannot do. It cannot seek out the ends of its severed radii and connect them with new filaments ; it cannot pick up the points of its damaged spiral and join them with new lines. I do not believe it can even contemplate, far less appreciate, the nature of the ruin. Such an act as this is outside its daily work. It can build up and it can tear down, but to repair a broken filament is beyond its feeble mind. Once the work of construction is over the sole duty of the spider is to sit at the centre of its snare and await the entanglement of insects. Injury to the architecture is then of no concern to the spider. When evening approaches the fabric will be renewed. The instinct to reconstruct will then impel the archi- tect to work ; but till that hour arrives it feels no impulse but to sit and wait. Let us consider the spider engaged in the con- struction of its snare. Is it then in the same sub- jection to its instincts as when it sits patiently waiting for its food ? It is fulfilling a complex and difficult duty. It is performing each act with mathematical precision. It is building up a fragile and harmonious texture, and every thread must be in place or the final symmetry will be lost. Through all this delicate workmanship is the spider an intelligent agent or only an unconscious tool ? Has it any power to modify 128 A NATURALIST IN HIMALAYA the nature or perfection of Its fabric, or is it but a slave to an instinctive guide? Can it see anything of the final beauty, or Is it ignorant of all Its work? Experiment will show. If I alter a snare so as to place difficulties before the spider, can the spider appreciate what has occurred and, by some simple device, remedy the defect? I find a web partially constructed which the spider Is busy bringing to a state of completion. The temporary spiral has been laid down and seven turns of the viscid spiral. The completion of the latter Is the earnest duty of the spider. It is moving from spoke to spoke, using the outer turn of the temporary spiral as a bridge by which to cross over. With a sharp pair of scissors I gently divide the bridge between two of the spokes. The spider circles on. It comes round again and meets the broken bridge. It shows some hesitation but does not interrupt Its work ; it continues inward till It meets the second turn of the temporary spiral and there crosses over. I have destroyed the spider's bridge. It has to pursue a longer journey at each circuit. It is obvious by Its hesitation that it feels something to be at fault. The remedy is clear ; another filament should be run across and a new bridge formed. It is the simple work of a moment, but the spider will not do It. It prefers to continue its longer round and cross by the inner bridge. I now divide the second turn of the temporary spiral in the same segment. The spider again takes no notice, but crosses over by the third turn. I divide the third turn and the spider crosses by the fourth. I divide the fourth turn and the spider has now to continue to the very centre of the snare before it can THE INSTINCT OF SPIDERS 129 cross over. It has to perform fully three times as long a journey and pay out three times as much line to complete the spiral in this segment than in any other segment, yet the spider works mechanically on. The journey, the labour, the confusion of the spider have all been increased. A single filament for a bridge and the work might continue as before, but the spider cannot see this. It made many bridges a few minutes before ; it cannot make a single bridge now. The reason is clear ; the time for bridge-making was before the commencement of the viscid spiral. In this snare seven turns of the viscid spiral are complete, and therefore the spider cannot build a bridge now. I continue the experiment. In one segment there are no bridges and the spider must continue to the centre of the snare in order to cross over. I now cut carefully across the centre, so that the spider in order to complete the segment will have to pass the centre and cross over by the temporary spiral of the opposite side. Even this does not move the spider to repair. It continues to perform its long journey over the damaged web, cross at every circle to the bridge on the opposite side in order to complete the spiral in that segment. The snare has by now lost almost all trace of its beautiful regularity ; the spokes which bound the divided threads have separated to a hand's breadth, while those on either side have approximated to the width of a linger ; that perfect parallelism in the spiral coils is lost ; threads adhere to one another ; in the narrowed segments they hang down slack ; in the wide segments they are tense to break- ing point ; the radial symmetry has become shapeless ; the snare is held in an uneven strain and it no longer K 130 A NATURALIST IN HIMALAYA has a centre. Yet the spicier works mechanically on. How blind is this instinct that impels the spider in this course ! A single bridge would improve matters ; it could not remedy them now, for the damage is too great. But it is all the same to the spider. To construct a bridge now is far beyond its mental power ; it can only circle mechanically on. I was amazed to think that a creature could be compelled by such a blind unswerving instinct to circle round and round the formless web, and driven by so unalterable a mental stimulus to weave such a shapeless and imperfect structure. I modified the experiment in different ways. I divided the outer bridges in two adjoining segments, but the spider crossed over by the second line of bridges. I divided all the outer bridges in all the segments, and the spider crossed by the second circle of bridges. I have no doubt that if I had removed the second circle, then the spider would have used the third circle ; or if I had removed the third circle, then it would have used the fourth circle ; but what it never would have done was to construct a new bridge. But one experiment will include all. I found a snare with twenty-one radii and a temporary spiral of six turns. The spider had commenced the viscid spiral and five turns were complete. I removed the whole of the temporary spiral in every segment. That is, I divided 126 possible bridges, so that the spider had now no bridge left in any segment. It must either build new bridges or continue right into the centre at every passage from radius to radius. It must either go back on its work or face tremendous obstacles. What will the spider do now? Its difficulties are THE INSTINCT OF SPIDERS 131 acute. All its bridores are o;one. The radii are slack from the loss of the scaffold ; they now wave and tremble in the air. If the spider can appreciate any- thing of the precision of its work, it must do something now. At first it is alarmed and hurries away to the edge of its snare. I can divide two, three or four turns while the spider continues in its course, but I cannot remove the whole spiral. In twenty minutes the spider returns. It again takes up its work, the con- tinuation of the viscid spiral. It meets with immediate trouble. It can find no bridge ; it moves with difficulty along the slackened radii ; its confusion is clear. But it makes no attempt to remedy the damage, no effort to lay a new bridge. Into the centre it travels at every segment except where the slack radii fall close together, when it can step across from radius to radius. Great disorder follows in its architecture. The loose radii confuse its sense of tension ; the little tags of filament perplex it and it anchors its line in the wrong place. All its attachments are out of order ; radii are glued to radii ; parallelism is completely lost. Con- struction continues, but the snare rapidly develops into a hopeless tangle. Yet the spider is satisfied. It still makes no effort to place new bridges between its radii. It cannot go back on its old work ; it is bound to its routine. A few turns of a temporary spiral would solve its difficulties, but this the spider is quite unable to effect. It would mean the commencement of the routine at some other point, while there is only one point at which the spider can commence, and that is the point at which the routine was broken. Still the spider labours on. Its difficulties overcome it. 132 A NATURALIST IN HIMALAYA Hesitating and perplexed, it works backwards and forwards from the centre to the circumference in the struggle to lay down its viscid spiral. The slack radii make it continually reverse where there should be no reverse. Aimlessly it gropes with its fore leg, seeking for the spiral to guide its measurements. It either touches nothing or, if it finds a filament, an attachment follows, usually in the wrong place. The difficulties of the spider increase at every turn, and greater con- fusion follows in its architecture. But it persists in its one duty, the only duty it can then perform, the construction of its viscid spiral. At length it ceases; its duty done. Satisfied that all is well, it seats itself at the centre of the snare surrounded by the hopeless tangle of its lines. How blind is the instinct that impels a spider in this fruitless course ! All the snare needs is a few bridges to stiffen the radii and allow the spider to pass over. But the spider neither sees it nor knows it. It under- stands nothing of its architecture. Each step must follow the preceding step. Each act has its determined sequence. The spider works unknowingly, driven by the clear, cold logic of events. At the obedience of an unswerving- force it strugfofles in its unconscious duty. Its instinct tells it that when at work on its viscid spiral it must continue till its viscid spiral is complete. This instinct the spider implicitly obeys, thoug^h it leads it to confusion. I will mention a few more experiments to indicate the blind instinct by which the spider is controlled. I found a snare of Araneus najitictis in which six turns of the viscid spiral were complete. The spider was busy continuing the work. It was monotonously THE INSTINCT OF SPIDERS 133 circling round the snare, crossing from radius to radius and attaching the viscid spiral to each radius in its pas- sage. I divided one radius immediately after the spider had attached to it the spiral. The spider circled on. It aofain came round to the severed radius. The radius being gone, the spider found before it a segment twice the normal width. It had to cross over two bridges instead of one, extend a line twice the previous length, as it had now to span two segments with the one line. Nevertheless, the spider did not seem confused. It made no attempt to replace the radius, but kept straight on. I then divided a second and adjoining radius so that the spider had to perform three times the journey and bridge a gap three times as wide as was required in the uninjured segments, yet the spider worked on. I divided a third and adjoining radius, subsequently a fourth, but still the spider continued its monotonous circuit. It made no attempt at any repair, but kept blindly to its routine. On severing a fifth radius, the bridge in the temporary spiral over which the spider crossed had not only become six times the normal length, but also so loose and slack that the spider found some difficulty in passing over it. The spider clearly felt something was wrong ; it checked its course round and round the snare ; it hesitated, ran back- wards along the lengthened bridge searching vainly with its legs for the broken radii. A few new spokes would solve its difficulties, nothing else was required, yet the spider could not do it. It made no attempt at any repair, but again continued the circuit. I divided a sixth radius. The bridge was now very slack and the spider very discomfited during the crossing. It was most amusing to see the little creature sweeping 134 A NATURALIST IN HIMALAYA its Ici;' through the air seeking for the lost radii. Nevertheless, it still circled on. A seventh radius was divided, so that now almost half the radii in the snare had been severed, and all were adjoining radii. The bridge was now eight times the normal length, and the space across which the viscid thread had to be drawn was eight times the normal width. Neverthe- less, the spider struggled on in the same mechanical routine until the division of the seventh radius made its difficulties acute. The bridge was now so slack that the spider could scarcely cross it, and I could almost have put my fist into the vacant space in the snare. The bridge was almost im|)assable, yet the spider persisted in its blind circuit, adhering rigidly to its routine. Instinct is the guiding factor of a spider's life ; it is instinct that compels it in the same undeviating course. Introduce difficulties in its circuit, raise increasing barriers to oppose the instinctive progress, build up obstructions to impede the blind routine, and the spider can do nothing to overcome them ; it can only struggle in its course. It can appreciate none of these difficul- ties ; it can understand none of these obstacles ; all it can do is but circle on. Another experiment leads us to a similar result, that the spider knows nothing of its work. A snare of the Aranezis was under construction. Four turns of the viscid spiral were complete. In one segment between two radii I divided the spiral as fast as it was laid down. Thus, with the exception of the four turns that existed before I commenced the experiment, no other filaments were allowed to remain in that segment. The spider circled round and round weaving with THE INSTINCT OF SPIDERS 135 accuracy its viscid spiral. Beautiful parallel lines were stretched across every segment except the experi- mental segment. In this segment was a vacant space, for I there divided the line as fast as the spider laid it. But the spider could not appreciate this, though every time it crossed the segment it found that its measuring line was lost. It worked unheeded. Twenty-eight times it drew a line across the experimental segment and twenty-eight times I severed it. The spider could not recognize that, although it was bridging this segment again and again, yet it was constructing no network. It circled on, ever diminishing the circum- ference of its spiral as it drew nearer to the centre. Finally it sealed off the end of the spiral and ran away to the centre to wait for entangled insects. The spider was satisfied. Without doubt it believed, that it had constructed a perfect snare and was quite oblivious of the fact that one whole segment was almost entirely absent. That the spider is a slave to its own instinct, that it is able to recommence its work only at the point where the instinctive round is broken, can be still further exemplified. I discovered a snare with the spider busy at its work. Ten turns of the viscid spiral were complete. I divided all the turns of the viscid spiral right round the snare so that only the hub, the radii and the temporary spiral remained attached to the foundation-lines. My interference disturbed the spider and it hurried away to the edge of the snare. I wished to know what it would do on its return. It would find a snare with a hub, radii and temporary spiral, but with no viscid spiral. What will it do .-^ Will it commence to lay down a spiral from the 13G A NATURALIST IN HIMALAYA beginning, or will it take up its work where it left off, that is at the eleventh turn ? The spider recovered from its alarm and resumed its work. Without hesi- tation it proceeded to where it had left off. It neg- lected to replace all the ten turns that I had divided. It commenced its work at the eleventh turn, and thus constructed little more than half a snare. It seemed quite contented with the structure, and I have no doubt would have considered it as excellent a snare as it had ever formed. That the spider cannot go back on its work still another experiment will show. A snare has just been completed. The viscid spiral has been sealed off and the spider has taken its post at the centre to lie in wait for insects. I divide the whole of the spiral in every segment. The snare now consists of a centre, radii and foundation-lines, but it no longer has a spiral. The force of instinct had just been fulfilled, and I wondered if the spider could start again on its routine and build up a new snare. The spider was unequal to the task. The reflex round was over, and not for twenty-four hours would the spider move to work again. It took up its post amidst the bare diverging radii. I do not believe it even had the power to appreciate that any damage had been done. Till dark I watched it solemnly waiting for insects that were never captured, for the snare no longer had a network. Fulfil the predestined plan is the doctrine of a spider's life. Not one can look back upon its woven chain nor retrace the slender links of architecture. The work is done ; it cannot be done again. The snare has vanished ; the naked spokes remain. But to the spider's mind the net is perfect, and relentless THE INSTINCT OF SPIDERS 137 instinct is fully satisfied. It cannot for an instant con- template its handiwork and witness the utter ruin. Reconstruction now is impossible. Another day must pass before the instinctive fire rekindles and the spider feels the call to work. I recalled in these connections the ingenious and oft-described experiment of P. Huber. He discovered a caterpillar which made " by a succession of processes a very complicated hammock for its metamorphosis ; and he found that if he took a caterpillar which had completed its hammock up to, say, the sixth stage of construction, and put it into a hammock completed up only to the third stage, the caterpillar did not seem puzzled, but repeated the fourth, fifth and sixth stages of construction. If, however, a caterpillar was taken out of a hammock made up, for instance, to the third stage, and put into one finished to the ninth stage, so that much of its work was done for it, far from feeling the benefit of this, it was much embarrassed, and even forced to go over the already finished work, starting from the third stage which it had left off before it could complete its hammock." The rhythm of the caterpillar's instinct was so mechanical ; the creature was in such abject slavery to its routine, that once the rhythm was broken it could only recommence at the point where the break took place, even though it might greatly benefit by commencing somewhere else. It is very similar in the case of the rhythm of a spider's instinct. The spider in the snare of ten turns is unable, after all the turns are destroyed, to commence in any other place than at the eleventh turn ; the spider in the snare without any temporary spiral continues to struggle on with its work, but is unable to reconstruct 138 A NATURALIST IN HIMALAYA a brido^e ; and the spider that has come to the end of its instinctive round by the completion of its viscid spiral is unable to commence again. Thus the spider is, like Huber's caterpillar, a slave to its own instinct. In a beautiful mechanical rhythm it toils onward in its daily task ; but break that rhythm and the whole chain of action is disturbed, and the only place at which the spider can again take up the thread of its motion is the place at which the rhythm was broken. As in a machine each movement follows another movement in an unalterable sequence, so do the far more complex motions of a spider's life follow one on the other in a long ceaseless rhythm. If we learn anything from these experiments, it is how feeble are the mental powers of the Arancus. He who studies for the first time the subtle device of a circular snare is full of wonder at the skill of the contrivance. He who watches for the first time the work of construction is amazed at the ingenuity of the architect. r3ut this is a false impression. There is no skill, no ingenuity in the sense that man would use it. There is little credit to the spider ; at least to the workings of its mind. It is ignorant of all it does. It can neither reflect on its past nor take thought for its future. It must act at any moment in accordance as its instinct tells it. It must fulfil each step in its architecture independent of any choice. It knows not why or how it does it, nor can it do aught else. It cannot go back one inch in its construction. The spider is an automaton. It learns little if anything from experience ; all its knowledge is innate. A definite sequence of events must follow and the spider must obey each step in the sequence. To ponder over THE INSTINCT OF SPIDERS 139 those events or to alter a sincrle link in the lonor chain of action is far beyond the simple mind of the Arancus. I pass now to another question. How will geo- metrical spiders behave when their snares are inter- changed? The snare of an Araneiis is made with such precision ; each line is so accurately measured by some portion of the spider's body that I fancy the complete structure is specially adapted to the movements of its owner. If we take a spider from a snare and place it on another snare, we see that the movements of the spider are more difficult in the new snare, and it often injures the fabric in its progress. The intricacies of the new snare are not suited to this spider. Each is best fitted to the product of its own precision. But a spider will often rest content with a snare other than its own. I interchange two Aranei, placing each on the other's web. They are first scared, hasten away to the foundation-lines, but, taking confidence after some twenty minutes, return to the centre. There they wait. They grow restless ; they test the radii with their fore limbs, vibrate the snare, make short explorations towards the circumference as though dissatisfied with their homes. Soon confidence in- creases ; they remain passive at the centre and seldom stir from the resting-place unless to seize an entangled prey. They are satisfied with the exchange. Each is probably quite oblivious of the fact that it is not in its own snare. I make a more marked exchange. I place an Aranezis in the snare of a Tetraznatha and a Tetra- gnat ha in that of an Aranetis. What will happen now ? The snares are more dissimilar. One is horizontal, the other vertical. The spiral of the Araneus is closely 140 A NATURALIST IN HIMALAYA wound, that of the Tctra^^natha more wide apart. The one is a narrow, the other a wide-meshed net. The spiders themselves equally differ. Araneus is a stout, compact, globular little creature with short quiver- ing limbs and hasty in all its motions. Tetragnatha, on the other hand, is a narrow elongated spider, with limbs disproportionately long and slender and, in its circles, moves with apparent method and precision. Each has just finished the construction of its snare. I make the interchange. At first there is the usual alarm, but soon the spiders settle in their new abodes. They accept the unnatural conditions and are satisfied. When I found that the Araneus accepted the snare of the Tctragiiatha and the Tetragnatha that of the Ara7iezis, I imagined that a geometrical spider had little choice in this matter and was content with any snare. But this proved to be a false opinion. I interchanged spiders when employed in their architecture. I took a Tetragnatha from a snare in which seventeen turns of the viscid spiral were complete and transferred it to a very similar snare of an Araneus in which only two turns were complete. I expected the work to continue in the new snare, but in all likelihood with greater difficulty. I was mistaken. After a period of hesitation which lasted for about ten minutes, the spider commenced to explore its new surroundings. It repeatedly shook the web as though it were discovering the direction in which the main foundations lay. It moved all over the network. It examined closely the radii, the temporary spiral, measured all the numerous intervals and made itselt thoroughly acquainted with the complexity of the new snare. But it remained unsatisfied. It refused to sit THE INSTINCT OF SPIDERS 141 in patience at the centre. It set about to demolish the snare. It moved out along each radius eating up the fabric in its progress. Methodically it worked until it had devoured all. When the snare had been com- pletely destroyed with the exception of the foundation- lines the spider then took up the work of construction. It began to lay a new snare in the foundations of its alien predecessor. The Armieus, which I removed from the snare completed up to two turns, I placed in that of the Tetragnatha completed up to seventeen turns. Now this was an advantage to the Araneiis. The new snare was more complete. Much of the work had been done by the Tetragnatha that it had replaced. If the Ara- neus'yx^l continued the work and brought the snare to a completion, it would gain much by the expenditure of less silk. But I felt sure that the spider could not do this. It first explored the snare. Then, unsatisfied with the exchange, it behaved like the Teti'-agnatha in the previous experiment ; it ate up the whole snare. All the new radii, all the complete bridges, the seventeen turns of the viscid spiral, just newly spun, were systematically destroyed. In this instance the spider was in a position to gain by the transfer. But it was unable to reap any advantage from the half- completed work. It must commence again from the very beginning. Similarly have I transferred Araneus nautiais while engaged on construction, to another snare of its own species. I have sometimes seen it rest satisfied with the transfer and resume the work, but often it de- stroyed the snare. I am unable to understand why a spider sometimes accepts and sometimes rejects a new 142 A NATURALIST IN HIMALAYA snare. It is not necessarily the snare that looks the most unsuitable and different from its own that the spider will destroy, for an Araiieiis may accept the snare of a Telragnatha. I have a note that points to some other cause. I once removed a spider from its half-constructed snare and, after a lapse of five minutes, replaced it again on its own snare. I saw no reason why this spider should not continue the work of construction, commencing again where it had left off. But it did not act as I had thought. It did not seem to recognize its own property. It first tested and examined the fabric on every side. Then, after a thorough exploration, it gobbled up the whole structure and commenced to weave a new snare. What can we say of a creature that cannot recognize the features of its own work ! The problem as to why a spider does not become entangled in its own snare was solved by the inimitable skill of M. Fabre. The only adhesive portion of the structure is the viscid spiral ; none of the other lines have any tenacious power. This is well displayed in spring. At that season clouds of pollen float down- ward from the pines, filling the air with a fine yellow dust. Innumerable grains fall upon the snare and adhere to its sticky lines. The viscid and non-viscid filaments appear in distinct contrast. The radii, the hub, the temporary spiral, the foundation-lines are all un- changed, but the viscid spiral is transformed into a continuous golden line. I repeated some of the simple but ingenious ex- periments of M. Fabre, conceived for the purpose of discovering why the spider did not adhere to its own viscid spiral. I touched the various parts of the snare THE INSTINCT OF SPIDERS 143 with a clean glass rod. The radii, the hub, the temporary spiral, the foundation-lines were non-viscid ; the viscid spiral alone adhered to the glass rod. I then smeared the rod with a thin layer of oil and found that the viscid spiral adhered more feebly to the rod when smeared with oil than when it was quite dry. I used a spider's leg in place of the glass rod. It did not adhere to the viscid spiral, but after moistening it thoroughly with benzene so as to dissolve away any oily coating, the leg immediately adhered to the viscid spiral. From experiments similar to these M. Fabre has discovered that it is the possession of an oily coating which prevents the geometrical spider from becoming entangled in its own web. A spider, I think, uses as far as possible the non- viscid radii during its movements in the snare, but this is not due to the fact that it would stick to the spiral, for I covered all the radii of a perfect snare with a thick coat of adhesive gum and the spider was well able to run backwards and forwards along" them. Spiders other than geometrical spiders become entangled in the circular snare. They do not possess the oily coat so essential to the Epeiridce. I took a species of Hippasa which constructs a non-viscid plat- form on which insects become entangled but to which they do not adhere. I placed the Hippasa on a circular snare. It was quite as helpless as any fly ; it did not attempt to creep over the snare, but was immediately entrapped. Moreover, its surface could not have possessed any fine coating of oil, for its legs adhered to the viscid spiral. Thus it is clear that geometrical spiders are perfectly adapted to move over the glutinous filaments of their webs. 144 A NATURALIST IN HIMALAYA Some facts may be of interest regarding the general habits of these spiders. When suddenly alarmed they behave in different ways. If the alarm is slight and the Araneus is at work on its snare, it immediately stops and remains perfectly motionless. If the alarm is greater, it hurries away from the scene of its labour and takes up a position in the centre of the snare from where it can move in any direction to attack the invader. If terrified, the spider deserts its snare, hastens away along a foundation-line and takes its stand beneath a sheltering blade of grass. Often, when two spiders are working in close proximity, the foundation-lines of the two snares may cross one another or may be attached to the same object. Under these conditions the spider of one snare some- times invades the other snare. The owner of the latter immediately recognizes the invasion, turns in the direction of the intruder, grasps firmly two of the radii and violently shakes the snare. The purpose of this, I think, is to warn the invader that he has crossed over into a hostile country and must immediately return to his own territory. The Ai'-ajieus sometimes acts differently when alarmed. It lets go the snare and suddenly drops down to fall amongst the underlying foliage. There it remains concealed but not lost. It is still connected with its snare by means of the filament of silk that it has emitted in its fall. In addition to dropping from its snare, the Araneus sometimes adopts a more com- plicated method of escape. It first drops, then, while suspended by its filament, it emits a number of additional filaments which are carried away by the breeze until their free ends find a suitable anchorage. THE INSTINCT OF SPIDERS 145 The spider then climbs away along ihe new filaments and escapes. The principle of protective resemblance is evident in the behaviour of these spiders. The Tetragnatha, when alarmed, remains perfectly motionless and thrusts forward the front two pairs of limbs, the tips of which diverge slightly from one another. This attitude is, I imagine, of some importance to the spider, for it no longer bears any resemblance to a living creature, but might be easily confused with the flowers of the grasses that on all sides surround the snare, and to which the structure is often attached. But there is in these hills another geometrical spider, unnamed, but belonging to the genus Cyciosa, which adopts a still more perfect method of protective resemblance. It envelops its captured flies in a coat of silk so as to form little pellets which it strings along one of the diameters of the snare, almost always, I think, in the vertical direction. The spider itself very closely resembles one of these silken pellets. It is of a brownish-white colour, and, when it tucks in its legs and remains motionless, it is not easy to tell which is the spider and which the pellet. The general shade of colour varies in different individuals. Some speci- mens, or it may be species, are distinctly browner than others, and the little pellets which they construct are correspondingly of a darker hue. But in addition to the close resemblance, the spider's position in the snare must be of great value, for it sits at the centre in the direct line of the row of pellets which are strung along the diameter on either side. So perfect is the resemblance that it is almost impossible to detect the presence of the spider unless it is remembered that it 14G A NATURALIST IN HIMALAYA always remains at the very centre, I showed the row of pellets to a friend, and told him that one of them was a living spider, I asked him to select it, and offered a wa^jer that he would not be correct in his selection. After a close scrutiny of the snare, he at length selected one of the pellets furthest away from the spider, and was then very surprised to see the central pellet climb out along the snare as soon as I touched it. I have even thought that the theory of protective resemblance might be applied to the snare itself. A circular snare, when spread over a pool, resembles sometimes a series of circular ripples flowing outward on the water from a central point. Flies are con- tinually alighting on these placid pools, and throw the smooth surface into circular ripples as though a pebble was dropped into the water. I have often been deceived by these ripples into the belief that I had discovered a circular snare, and I expect that an enthusiastic supporter of the theory of protective resemblances would claim this similarity as of great advantage to the spider, by deceiving the sharp eyes of insectivorous birds. But to my mind this would be only a fanciful belief. The special senses of animals, their potency and even their very existence, have often supplied a wide field for experiment and discussion. I wished to satisfy myself as to the presence and activity of these senses in the geometrical spiders. I made some experiments to test the sense of taste in spiders. I placed a large fly in a strong solution of quinine and gently laid it on the snare of an Aranens. Now, whenever an Araneus captured a small insect it THE INSTINCT OF SPIDERS 147 was in the habit of devouring it at the site of capture, but, if the insect was large, it used first to bind it in a few coils of silk, and then, carrying it away to the centre, used to eat it at its leisure. On approaching the large fly soaked in quinine, the spider first seized the insect but instantly drew back as though it had discovered something distasteful. It then commenced to coil round the fly a thick mass of silk and to shake the web in the endeavour to cast out the bitter morsel. When the fly was thoroughly concealed in the covering of silk the spider returned to the centre but left the fly behind. It appeared agitated and unhappy ; it continually brushed its mouth and jaws with its fore limbs as though to remove something irritating or oflensive, and at intervals forcibly vibrated the snare in the hope of dislodging the distasteful insect. On another occasion I soaked a much smaller fly in the quinine solution. The spider behaved in a similar manner, immediately rejecting the insect after first tasting it. I am confident that in these experiments the cause of the rejection of the insects was the unpleasant flavour of the quinine. This substance has no odour and causes no irritation. The species of fly was one that the spider always eagerly devoured, and the spider did not reject these flies when soaked in other taste- less fluids. Consequently I felt satisfied that the geometrical spiders possess the sense of taste. Camphor is a useful substance for testing the sense of smell. I placed flies in a solution of camphor and then laid them carefully on the snare. The spider came forward to examine them. It did not appear to notice any sign of an unnatural odour, but immediately 148 A NATURALIST IN HIMALAYA swallowed the Hies. Camphor is a germicide and injurious to insect life, and I have no doubt that it would be equally harmful to spiders. I have before mentioned how certain ants are instantly driven away by the odour of camphor, but the Araneus passed it unobserved. It did not seem to recognize the strange substance, and I doubt whether it possesses any more than a rudimentary sense of smell. I believe a spider often sees the flies becoming entangled in its snare. It does not work by the power of touch alone. I feel sure that an Ai-aiieus, which I once observed descend to attach the vertical line of its snare, was able to detect the presence or absence of a suitable anchorage from a point eight inches above the surface of the water. I have seen an Araneus rush out along a radius in the endeavour to catch a fly that came dangerously close to, but did not touch the snare. Also I observed a spider drop down from the centre of its web to a distance of about three inches in order to seize a fly passing underneath. In both these cases, however, the stimulus may have affected the sense of hearingr rather than that of sigfht. Touch, I am sure, is the most accurate and sensitive of all the senses. It is by touch that a spider ensures the shape, the structure, and the symmetry of its snare. Its limbs are rule, compass and dividers with which it weaves its perfect plan of architecture. More- over, it is ambidextrous, measuring with either limb as it circles to right or left. It is by touch that it discovers the entanglement of its prey. Another spider far away on the external frame is instantly felt and distinguished from a captured insect. Imitate how you will the entanglement of a fly, you cannot THE INSTINCT OF SPIDERS 149 deceive the spider's fine sense of touch ; it will not hurry out to seize a capture, but violently shake its snare to repel an enemy. How accurate, how discriminating is this sense of touch ! A snare extends from bank to bank at the brink of a cascade. As the waters pour over the rocky ledge and splash in the pool beneath, hundreds of little drops leap up and strike against the snare. At every stroke the fabric quivers, but the spider sits unmoved. The slightest touch by a passing fly and it rushes out along the quivering line. But the vibration of the drops of water no more mislead it than do the tremors of the wind. There can be few creatures that possess so fine a tactile sense as the spiders that construct geometrical snares. " The spider's touch, how exquisitely fine ! Feels at each thread, and lives along the line." I have now concluded my remarks on the geo- metrical spiders. I find that they are endowed with acute senses in relation to the outer world. They see, hear, taste, and have an exquisite sense of touch. But their minds are an utter blank. They know nothing of their lives. They are oblivious of all their subtle skill. They lack the faintest glimmer of knowledge, the flimsiest conception of the why and wherefore of it all. They can no more reflect upon their past nor retrace their thread of architecture than they can conceive the nature of their toil. CHAPTER IX SHEET-BUILDING SPIDERS Habits of spider and character of snare — Refusal to spin in stormy weather^Mode of capturing prey — Injection of poison — Sense of touch — Function of pedipalps— Force of instinct — Shaniming death in spiders and insects — Physical properties of web — Pertinacity of Ariema. Every nook and cranny in these hills was used as a lurking-place by another common genus of spider that constructs its snare in the form of a non-viscid sheet. This is the genus Hippasa, and the species most probably H. olivacea of Thorell (see Plate, p. 88). The sheet of web, continuous with the funnel-shaped tube at the mouth of which the spider waits in hiding for its prey, is so well known as scarcely to need description. The sheet is composed of such an enormous number of tiny threads that at first sight it seems incredible that the spider could lay down so dense a network of single lines. After observing the spider at the construction of its snare, it soon became evident that, unlike the geometrical spider, it worked with a bunch of filaments and not with a single thread. After a scries of single foundation-lines had been drawn from point to point so as to form a scaffolding for the snare, the spider commenced to emit a sheaf of filaments and to wander in a haphazard manner backwards and forwards from side to side, attaching the sheaf to suitable points until the fine sheet of 150 SHEET-BUILDING SPIDERS 151 webbing was complete to satisfaction. There is no geometrical accuracy in this structure. Nor is there any viscidity in its lines save at the points of attach- ment of the filaments. Insects are captured by entanglement in the fine meshes and not by adherence to its lines. Instantly an insect alights on the snare its feet and wings become entangled in the meshes. With a little struggling it can usually break free, but the hungry, evil-looking spider, crouching near the mouth of its retreat, dashes at terrific speed across the snare and seizes its victim before it can escape. It is a most extraordinary fact that a spider can move about so freely on the snare without ever getting its own legs entangled in the meshes. With a magnifying glass it can be easily seen that the spider possesses three little curved claws at the tips of the tarsi, and that at every step these claws hook over a filament of the web. If the tips of the claws be removed with a fine pair of scissors the spider will move over its snare with much greater difficulty, hooking up a thread here and there, thouQrh it will not become entangled. It is difficult to understand how the claws never succeed in becoming caught in the meshes and impeding the progress of the spider, yet this never occurs no matter how tattered and broken the snare may be. It is strange to witness a spider darting with such incredible speed over its snare that its movements are almost impossible to follow, and to recognize that at every one of the little steps that go to make each movement, twenty-four tiny curved claws are hooked over various filaments in the web, and that these claws, though apparently just the very implements suitable for entanglement, are 152 A NATURALIST IN HIMALAYA raised and lowered and hooked around die filaments with such perfect precision that under no condition whatsoever do they become entangled in the snare. I was interested one day in observing that the Hippasa was actually able to burrow through the substance of its snare. A wasp of the species Polistes hcbrc€iis had become entangled. The spider dared not attack so formidable an enemy, but slunk away to the edge of the snare. The wasp, in its struggles to get free, dragged the web to pieces and succeeded in confining the spider beneath a fold of its own snare. The spider, nothing daunted, flexed its limbs, deftly separated the filaments of its web, very rapidly burrowed its way up through the body of the snare, and set about the work of reconstruction. Such is the freedom of the Hippasa when moving amongst the intricacies of its own lines. These spiders have learnt the lesson of the use- lessness of snare-construction in stormy weather. Heavy downpours of rain, occurring at frequent intervals and sometimes lasting for many days, break upon these hills. At such periods the spiders remain in their little rocky clefts and never attempt to con- struct a snare, knowing full well that it would be broken to fragments by the next downfall. The Hippasa displays a most remarkable instinctive power in the seizure of its prey. It injects the poison into the one vital spot that will instantly paralyze its victim. One might almost be led to believe that these spiders were acquainted with the minute anatomical structure of insects. It is very essential to the spider that it should know how to render its prey immediately nuiescent. It must strike suddenly and with instari' SHEET-BUILDING SPIDERS 153 taneous effect. For when an insect becomes entangled in a snare and is struggling to escape, it forcibly exerts its legs and wings in the attempt to tear itself away. By the force of these violent efforts it often does escape, and on all occasions injures the snare. The move- ments of the legs and wings cause the greatest damage, so it is necessary that the spider should quickly subdue these and render its prey helpless. The movements of these parts are under the control of a nervous ganglion situated in the insect's thorax, and the spider acts as though it were well aware of this fact. It behaves as though it understood that the thorax is the vital spot and that into the substance of this part it must strike. On every occasion on which I have observed the spider seize its prey it has struck un- hesitatingly straight into the thoracic ganglion, pro- ducing an immediate paralysis of the legs and wings. It behaves with a similar skill to the tarantula of M. Fabre, that struck into the one vital point in the whole nervous chain. Wonderful as are the instincts of the geometrical spiders in the weaving of their beautiful snares, no less fascinating are the instincts of this humbler species in the exactness of its knowledge of the vital anatomical point and the perfect precision of its stroke. I think it is a matter of some doubt amonor natural- ists whether or not the smaller species of spiders actually inject poison into their insect prey, I am inclined to believe that they do. For an insect, after being seized by the Hippasa, is paralyzed in an extremely short space of time, far shorter than could \ result from mere penetration of the thorax. The legs and wings are in an instant struck motionless, If th§ 154 A NATURALIST IN HIMALAYA thorax of an insect be penetrated with a pin or even the interior of the thorax entirely destroyed, the legs and wings are not paralyzed for a long time, possibly for days, yet the destruction of tissue is much greater than that produced by the spider's fangs. The rapid paralysis seems therefore to be due very probably to the injection of a minute quantity of a powerful nervous poison. The Hippasa lurks at the entrance to its tunnel with its subtle snare spread out before it. There would seem to be little doubt that it is waiting and watching for its prey. But this may not be strictly true, for the sense of sight does not appear to be very acute in these spiders. They are directed towards their prey by the help of the vibration of the snare rather than by the power of vision. It is possible to move a fine needle from side to side in front of the spider's head without it showing any sign of being aware of the strange object, but touch one of the filaments ever so gently with the needle and the spider is off at lightning speed. I also noticed in some examples, which I kept captive in a box, that they were able to detect the aerial vibrations caused by buzzing flies, but would be quite oblivious of their presence when the insects crawled close by along the floor of the box. But once a fly touched a filament then the spider became instantly alert and darted towards the capture. The pedipalps are to the spider what the antennae are to an insect, or the hands to a human being. They are all-important organs on which the creature's livelihood depends. Neither does the sense of hearing nor that of smell reside in the pedipalps, for the SHEET-BUILDING SPIDERS 155 spiders of this species respond to sound vibrations and to the odour of camphor after the pedipalps have been removed. But I beheve they possess a most exquisite sense of touch and that by their means the spider is able to detect the finest vibrations of its snare. This might be expected from their anatomical position, for they do not extend forwards like the antennce of insects, but are bent downwards beneath the spider's body, and not only rest on the snare, but move about on it in a manner resembling" limbs. The importance of the pedipalps is shown by the results that follow their amputation. After the pedipalps are removed the Hippasa can still construct a snare, but it resembles the architecture of the A^'aneus after the amputation of its fore limb ; it is a tangled and a shapeless fabric. The spider, when deprived of its pedipalps, crawls about clumsily ; it has lost much of its skill and pre- cision. It continually catches its feet in the filaments of its web, an act which, in the uninjured spider, never occurs, and I have even seen it tear the snare in the endeavour to free its limbs. Without its pedipalps, the Hippasa can no longer capture flies. It seems to be quite unable to detect the vibrations that follow on the entanglement of its prey. I doubt if its hearing is affected, for I have noticed it extending its fore limbs towards the sound of a buzzing fly as though it were a man deprived of its eyesight and groping in the dark. I believe it had lost a sense as important to a spider as is sight to a human being ; it had lost the sense of touch. A little incident illustrating the force of instinct in this species rather amused me. The Hippasa was waiting for visitors at the entrance to its tube and the 156 A NATURALIST IN HIMALAYA shell of a fly, long since emptied of its juices, lay rejected on the snare. An unwelcome visitor in the shape of a stinging wasp came buzzing by and entangled its feet in the spider's snare. Now the Hippasa, though armed with fangs and poison, is by no means valiant ; though fierce enough with harmless flies, it will not join battle with an angered wasp. However, on feeling the vibration of the snare it darted forward, but, on perceiving the nature of its capture, it halted for an instant and then sprang swiftly back. But the presence of the wasp seemed to have imbued the spider with an impelling instinct of capture, a feeling that, if it could not seize the wasp, it must seize something, for it again darted forward with equal rapidity, not to attack the stinging wasp, but to sink its fangs deeply into the rejected remnants of the fly. It is dangerous to interpret insect emotions in terms of human feeling, but it was difficult not to conclude that the entangled wasp had aroused in the spider that instinct which compels it to rush forth and seize an insect, and that the instinct, being first foiled by the fierce nature of the prey, yet still impelled the spider on until it finally attained its unprofitable fulfilment in the body of the empty fly. The force of instinct is remorseless. It must be satisfied even in a useless end. We see similar instances of this blundering, mis- guided instinct all through the animal world. I have already mentioned how the harvesting ants will some- times during times of famine store up grass and pebbles in the nest, not that this material is of any use to them, but because they feel compelled by instinct to gather something, and there is no grain available for them to collect, Also I have shown how the car- SHEET-BUILDING SPIDERS 157 nivorous ants, Myrmecocysttis, will ferociously attack an injured comrade, not because they owe it any hatred, but because they associate the injury with the presence of an enemy and, being unable to find this enemy, they satisfy their instinctive sense of battle by turning on their own kin. So also it is with many of the higher animals. I was once told of a tiny kitten that was reared from birth in a cigar-box. It recognized the safety of its cradle, and when alarmed used to hurry away to hide itself in its little home. At length the kitten grew into a big cat, but it still retained the instinct of its early days. It seemed to believe that its first home was still its sure place of refuge, for whenever it thought itself in danger it used to dash away and squat over the old cigar-box, though now little more than its feet were able to fit inside. Surely this was a mistaken instinct, for the cat could find no safety there. Similar instances are to be found even amongst the monkeys. I once saw a monkey so annoyed by its owner that it flew into a passion. It was full of resentment, and it hissed and snarled at its master. But just as in the case of the angry spider and the well-armed wasp, so also did a similar behaviour occur in the case of the enraged monkey. It dared not attack its master, but the force of instinct impelled it to attack something, and it fastened its teeth upon a chair. So also it is among^st the most intelliofent and social of beasts. In their case this miseuided instinct leads them into horrible and cruel acts. For just as the carnivorous ant will rend in pieces the disabled members of its own nest, so also will the saoracious elephant turn on the wounded of its own kin, or will 158 A NATURALIST IN HIIMALAYA a herd of oxen led by the same blundering- Instinct ferociously attack an injured comrade until they gore it to death. I noticed that, after catching these spiders in a glass tube so that all mode of escape was cut off, they used, after running up and down the tube a few times, commence to feign death. I do not suggest that the spider voluntarily placed its body in the posture that it thought it would occupy after it was dead, for I greatly doubt if so lowly a creature could have any mental idea of what that posture would be. But certainly the posture of death was that which the spiders did assume, for I allowed some specimens to die in order to satisfy myself of the fact. The Hippasa has instinctively learnt that it must first rely on its great speed to effect its escape, and that, when its retreat is cut off on all sides, its last resort is to lie absolutely motionless and pretend that it is dead. This is often an excellent mode of escape and not at all uncommon amongst both spiders and insects. A cantharid beetle, with a red prothorax and dark metallic blue wing-covers, often found in the valley, used to sham death in the most perfect manner. When touched, it immediately became motionless, flexed its head, turned its antenna; beneath its body, bent in its legs and appeared quite dead. Another much larger form belonging to the genus Mylabris of the same family, with conspicuous wing-covers banded with warning colours of bright yellow, also feigned death and, when alarmed, sometimes remained in that state for over a minute. A very similar species of the same genus, coloured with red bands and usually found at higher altitudes, remained absolutely motion- SHEET-BUILDING SPIDERS 159 less for two minutes with little yellow drops of acrid fluid exuding from the joints of its tarsi. It is curious that, in addition to flight, this insect has three other modes of defence, by shamming death, by a display of warning colours, and by the secretion of an acrid juice. Weevils {Cu7'culionidcc) are a group of insects that commonly sham death. The characteristic feature of their attitude is the position of the antennae. Normally the antennae are angular and project forward very much like those of an ant, but when feigning death they are turned downwards and curved in beneath the flexed head so as to be completely hidden from sight, and this is also their posture when the insect is really dead. But a weevil will not sham death when it would be more advantageous to adopt some other mode of escape. It seems to have some sense of discrimination in the matter ; for I placed one near the entrance to a nest of carnivorous ants and, when attacked, it never for a moment attempted to sham death, but rapidly took to its heels. But the best instance that has come under my notice of the strange practice of feigning death was in the case of the butterfly Libythea myrrha. This little butterfly is swift and erratic in its flight ; it is protectively coloured on its under surface so as to closely resemble a dried leaf, and in its movements through the air it looks very like a moth. I once observed the common bulbul, Molpastes leuco^enys, make a sudden attack on this butterfly. The Libythea was fluttering across a dusty path when the bulbul dashed swiftly on it. But the insect appeared to be well aware of its danger, for it instantly checked its flight and literally threw itself to the ground. Thus 160 A NATURALIST IN HIMALAYA the bird missed its prey and the butterfly looked to all appearances dead. I went to pick it up, thinking that it must be either dead or injured since it did not rest upright, but rather lay on its side like a leaf in the dust. However, it was far from really dead. I had no sooner touched it than it raised itself from the ground, opened wide its wings and flew uninjured away. This seemed a good illustration of the principle of feigning death ; there was no doubt that the Libythea was well aware of its danger and saved its life by adopting the simple ruse of hurling itself to the ground, where it lay motionless pretending that it was dead. I have mentioned these instances to show how general is this instinct both amongst spiders and their prey. Whatever may be its origin, it is a very real and valuable behaviour, and the fact remains that the attitude adopted by the species when feigning death is the same as that assumed when the spider or insect is actually dead. Before leaving the Hippasa I may mention a few physical properties of the webs of spiders that some- what interested me. The first was the remarkable power possessed by the web of the sheet-building spiders in preventing evaporation in the air beneath it. One species of this tribe of spiders used to con- struct its sheet amongst the rank grass or over hollows in the sand. During the night a deposit of dew used to form on the under surface of the web, and one would think that the warm sun would quickly evaporate the cluster of dewdrops that hung from the silken snare. But the sun did not seem to have the power, for the drops remained. I did not take much notice SHEET-BUILDING SPIDERS 161 of this until I saw the same occur in the broiHng heat of the Euphrates valley. There some little spiders used to spin their sheets of web close to the river. In the mornings they were often spangled with dew. Then the sun would rise ; its rays would grow intense the moment it appeared ; the temperature would slowly creep up to ioo° F. ; the sands would burn to the touch and the air quiver with shimmering heat, but the glittering drops would still remain suspended from the sheet of silk. Of such protection is this webbing that, even at midday in a broiling sun, I have seen the drops still pendent on the sheet. No doubt this property is of value to the spider in retaining for its use a plentiful supply of moisture. Another physical property of the spider's snare which adds still further to its own intrinsic beauty is its power of separating the white sunlight into its primary constituent rays. We see this best in the circular snare when it is stretched between a pair of pines high above us in the forest. The snare is sus- pended in the vertical line, the sun is approaching the zenith, and we look from below at a steep angle into the snare so as to see the sun's rays streaming down through it from above. We look up at it through the dark trees ; we can scarcely see it against the clear sky, when suddenly it becomes suffused with a lovely glow and a rich stream of coloured light illuminates its silken lines. Every filament has become a prism ; the sun's white light is broken into many parts and the whole circle of the silken fabric trleams with a rainbow light. It is a vision of transient beauty amidst the conifers when all around is the silent forest wrappc^d in a gloomy shade. M 162 A NATURALIST IN HIMALAYA I fear I have wearied my readers with this loiiL!^ account of my observations on spiders. I wish I could give them a httle of the pleasure that I obtained in making them. I will conclude with an incident illustrating their strength and pertinacity. Spiders of the genus Ariema spin a snare in the form of a tangled network of stay-lines supporting below a concave hammock. The spider hangs head downwards from the under surface of the hammock, and, whenever an insect becomes entangled in the stay-lines, it violently vibrates the snare in order to shake the capture down into the hammock. On one occasion I watched a large moth strike against the stay-lines, meet with immediate difficulties and soon tumble down into the quivering snare. The spider instantly seized the moth by the tip of the abdomen, while the struggling insect, in its efforts to escape, broke through the floor of the hammock. The moth was now unsupported by the snare, but was held firmly in the spider's fangs while the latter hung head downwards by its hind claws from a filament of the snare. This genus of spider injects no poison ; it has no knowledge of the vital anatomical point ; it subdues its victim by its own strenoth. Now the moth was at least six times as large as the spider and must have been an enormous weight for that little creature to support ; moreover the moth, by continual struggles and vibrations of its wings, endeavoured to escape, and it seemed as though at any moment it would break free. Yet the spider continued to cling with its hind claws to the filament and to maintain its fangs fixed in the abdomen of that unsupported struggling moth. It persisted in that attitude, stubbornly refusing to let go its prey, and not SHEET-BUILDING SPIDERS 163 till five hours had elapsed did it fall exhausted to the ground. Its strength but not its determination had failed, for its fangs were still buried in its victim. I had long since ceased to be surprised at the wonderful instincts of spiders, but I had never believed that they possessed such brute strength and resolution. CHAPTER X OBSERVATIONS ON INSECT LIFE Mountain dust — Inhabitants of pools^Carnivorous flies — Water-boatmen — Struggle for life — Mentality of fishes — Habits of Vespa orientalis — Nest of Polistes — Depredations of Vespa juagnifua -Mimicry in humble-bees — Humble-bees and flowers — Habits of leaf-cutting bees — Instinct of mud-wasp — Instinct of digger-wasps. Temperature and season greatly influence the aspect of a country. They are the common agents of physical change. Their action in this valley presents one feature deserving of our notice : the cloud of fine dust that daily fills the sky. In the oppressive days of summer, when for weeks no rain may fall, a dense haze collects over the mountains. It hangs thick over the valleys, and, like a veil, envelops even the highest peaks. The burning cliffs radiate a fierce heat and there is scarce a movement in the breathless air. All objects are obscured as though in a dim mist. The trees are unreal ; the hills are ill-defined ; they look bleak and uninviting, as though we looked through a moist fog on to a rocky shore. From a summit we obtain no sight of a distant range, and the plains are concealed beneath a shroud of dust. The atmosphere looks polluted, foul and murky, a vision of discomfort. Sickness increases. All vitality is lost when the cloud of heat obscures the sky. This haze is due to the permeation of the atmosphere with a very fine dust carried up by ascending convection currents 164 o % » «M.- O z I a X u. M a z 3 [/) < 0. a s H 'r^ >«^) f OBSERVATIONS .ON INSECT LIFE 165 generated by the contact of the air with the heated rocks. That these currents rise with great force from the valleys is indicated by the ease with which the plumed seeds are swept aloft from between the cliffs into the open sky, or the way in which a rain-cloud pouring over a ridge is opposed by an ascending stream within the valley and driven upwards as though in wreaths of smoke. The mornings show a clearer sky. The dust has settled in the cool of night. But it is only a temporary lapse ; the haze again deepens with the daily heat. Nothing but rain can now purify the air. At last the clouds collect over the hills ; first in silvery wisps increasing each evening into heavy cumuli, and backing away at night, leaving a clear sky. Finally the clouds burst ; a sense of relief is felt as the rain pours down in torrents. The sky clears and we see that the haze of dust has been swept to earth. A vast panorama is now exposed ; thousands of square miles of mountain are seen in a single view. All that was wrapped in gloom appears through a transparent sky. So clear is the prospect that every object looks magnified as though drawn miles nearer to our vision. Shadows cast by a passing cloud or by a mountain side roll across the clear valleys. Sinuous rivers sparkle in the sunlight ; tiny villages or strips of cultivated soil, hiding in some narrow glen, for the first time appear to view ; the nearer hills are tinged with blue as if reflecting the azure of the sky, and the snowy peaks climbing above the wooded slopes contend with the whiteness of the clouds. Thus do the waves of heat, risinp- from the enclosed valleys and lifting the finest particles of dust, darken 166 A NATURALIST IN HIMALAYA the sky and hide the face of Nature. Plains, whole mountain ranges, even the very sun, ar^ blotted from our view. At last the thunder-clouds burst ; torrents of rain descend ; the veil of dust is swept to ground and a new world is exposed. Animal life continues to flourish amidst this chano^ino- scene. In the streams that rush down the wooded slopes or flow more gently through the rounded hills are many forms, all competing for the right to live. Fresh-water crabs creep lazily through the pools. They did not seem to struggle hard for life, yet even these crabs had their own device by which to seize their prey. One day I observed a fresh-water crab eagerly devouring a dead frog. As I never saw dead frogs floating in these streams, I felt sure that the crabs must capture their prey alive. They were not very active animals and usually remained at the bottom of the pools, so I wondered how they succeeded in catching the sharp and nimble frogs. In another pool the little problem was solved. On first searching the water for any sign of life I detected nothing but a few tadpoles ; then, on looking more carefully, I saw the tips of a pair of large claws projecting from beneath a quantity of bright green water-weed. Not a trace of the body was visible ; nothing but the pair of limbs widely separated, with the claws partly open, clearly showing that the crab was lying in ambush to seize a passing animal. There were no frogs in this pool, so I removed one from the stream and gently lowered it towards the extended claws. The crab immediately darted from beneath its green hiding-place, clutched the frog in its strong claws and scuttled away beneath OBSERVATIONS ON INSECT LIFE 167 the overhangincT bank. Thus do the crabs, though the most shiggish creatures in the pool, gain their Hvehhood by a subtle skill. I suspect it is similar in the depths of the ocean, and that there the crabs and lobsters lie in hiding amongst the sea-weed and the stones to pounce suddenly upon their prey. Dragon-flies [Odonata) and sometimes robber-flies (Asi/idcc) loved to haunt the streams. The dragon- flies came, not only for prey, but to lay their eggs in the water. One large and beautiful species, with a black and green thorax and banded abdomen, used to alight on the grass and dip its abdomen deep down into the water ; while its partner, hovering just above, dashed furiously to attack any strange dragon-fly that dared to invade the sacred precincts. Dragon-flies must be included amongst the few enemies of ants. After a heavy downpour of rain flights of male and female ants belonging to a small yellow species used sometimes to congregate in a cloud and hang in the air near the banks of the streams. The dragon- flies then took a heavy toll of their numbers, darting hither and thither through the swarm like a flock of insectivorous birds amono-st a flio^ht of termites. The AsilidcE used to lie in wait for prey usually on a projecting spur of limestone. These flies, as is well known, capture insects on the wing, drive their sharp beaks into the bodies of their victims and suck up the body-juice. In dealing with smaller prey, such as a house-fly or a Syrphid, it simply drives its beak straight into the abdomen of its victim. No more cunning is required. This is sufficient to subdue its capture. But it is different with stronger species. I watched an Asilid that had seized a moth. The 168 A NATURALIST IN HIMALAYA robber- fly lay astride the back of its prey, gripping it tenaciously with all its limbs. So firm was its hold that the victim could not possibly escape. The fore tarsi of the fly were hooked round the anterior edge of the front wings of the moth ; the median tarsi similarly held the hind wings ; the hind tarsi closely grasped the sides of the moth's abdomen, while the beak of the Asilid was driven deep into the thorax a little to the right of the median line. In such a grip a moth is helpless ; its wings and abdomen are held as in a vice. It resists, but its struggles are in vain. It rapidly dies as its juices are sucked away. What strikes the mind in a contest of this nature is the skill with which the Asilid controls the wings of its prey and the strength of its grasp from which there is no possible escape. This insect needs no poison to stupefy its captures. Its strength and skill suffice for all its needs. It can overcome so powerful an insect as the cicada, and one so well armed as the humble-bee. I paid more attention to those very common little water-bugs, the Noto7ieciid(E, known popularly as water-boatmen. They were the most numerous element in the society of the pool. I often wondered why the frogs did not attack the boatmen, for it was obvious that they never attempted to seize them, though the boatmen often nibbled at the frog's hind legs. I thought that most probably the boatmen were possessed of an unpleasant taste ; yet this was not so, for the frogs eagerly devoured dead boatmen when thrown into the pool. The Notonectidcc escape the frogs by their great activity. The frogs recognize their inferior skill and never attempt to attack the boatmen. They have learnt that for these insects OBSERVATIONS ON INSECT LIFE 169 they are no match. Thanks to their nimbleness the water-boatmen are secure from attack. The only creature that I have seen successful in capturing them has been the water-scorpion, Nepa, and it succeeds by its stealth rather than by skill. It lies in ambush until a boatman comes between its wide-opened anterior legs furnished with strong blades. Then suddenly the blades come sharp together and the boatman is secured. The Noto7iectidc€ are predaceous in their habits. They capture the small insects that tumble into the pool. One peculiarity in their mode of feeding interested me. Anybody, who has carefully watched these water-bugs, must have noticed that at intervals they swim down into the water and maintain them- selves absolutely stationary some little distance beneath the surface by very rapid vibrations of their hind limbs, specially modified for the purpose of swimminpf. I could not understand the sigrnificance of this habit until I saw the boatmen dealing with their insect prey. I noticed that, immediately after capturing an insect on the surface, the boatman would descend with its victim and literally hover beneath the water with its struggling capture until the insect was drowned. I therefore conclude that this habit of repeated submergence has been developed by the boatmen to enable them to drown their insect prey. The boatmen do not confine their attacks to the smallest insects, as their powers of swimming are sufficiently strong for a single insect to drag beneath the water and drown a beetle six or eight times its own size. They are cannibals, not only eating their own dead comrades, but attacking them when 170 A NATURALIST IN HIMALAYA wounded or dying. Water-boatmen, when handled, sometimes give a sharp bite. I am sure they inject a small dose of poison, as the numbness remains for twenty-four hours and resembles that of a bee-sting. I suspect that the boatmen, in addition to drowning their prey, possess also the power of injecting poison into the insect, especially if its struggles make it difficult to control. The manner In which these insects swim on their backs is their most interesting feature. The long hind legs make a most perfect pair of paddles, and the plan on which they work may be easily observed when the boatman is placed in a glass of water. From the posterior margin of the tibia and tarsus there is directed backwards a double fringe of delicate hairs. At each thrust of the limbs these two fringes separate; the hairs spread out so as to form a broad resisting blade through the medium of which the pressure is exerted on the water. As the limb is again brought forward the fringes collapse, and a narrow edge, offering the minimum of resistance, is now presented to the water. We know that in flight the point of the wing of a bird or insect not only moves to and fro but traces in the air a succession of ellipses. I think it is possible to detect a similar motion in the swimming-paddles of the water-boatmen. They not only oscillate but also rotate. It is difficult to follow this in the rapidity of their motion, but, when I placed the insects in a glass of water coloured with methylene blue, I felt certain I could see the particles of pigment being whirled round in a spiral at each rotation of the limbs ; but it is difficult to be confident of this observation. OBSERVATIONS ON INSECT LIFE 171 I made a few experiments to test the special senses of the NotonectidcB. I think that they appreciate the events in their own Httle world almost solely through the organs of sight and touch. It is obvious that they possess the power of vision. One has only to look at their large eyes and observe the manner in which they dart under the water at one's approach to a pool to be satisfied that their sense of sight is acute. They do not appear to be fastidious in their taste. I drop some evil-smelling Heteroptera and other nauseous insects into the pool ; the boatmen dart out and eagerly devour them. I throw some bitter alkaloids into the water, but the boatmen take no notice. I place some boatmen in a basin of water and let fall close to them a few drops of a solution of quinine ; the boatmen remain unaffected ; the quinine no more disturbs them than the fall of drops of water. I throw them some insects injected with quinine ; the bitter morsels are eagerly devoured. I give to one a frag- ment of a strychnine tablet ; it is seized and carried down beneath the water as though it was an appetizing prey. I cannot, therefore, think that the NotonectidcB possess much sense of taste. I doubt if their power of smell is any more acute. They certainly did not behave like ants and spiders and recoil from the presence of camphor, but, rather, dealt with it in the same way as they treated the strychnine. Nor does their sense of hearing enlarge much further their prospect on life, for, if care be taken that the experimenter is not seen by them, he may shout, clap hands or blow shrill whistles without alarming them in the slightest. It is, I believe, through the sense of touch that they "live and move 172 A NATURALIST IN HIMALAYA and have their beinof." The moment the tiniest insect falls on the water the boatman is instantly aware of the surface vibrations and darts like lightning on its prey. A few experiments will soon make evident this delicate sense of touch. I place some boatmen in a basin of water ; they swim about content. I approach one with the point of a fine needle. It takes no notice. I bring the needle so as almost to touch the boatman, but it excites no sense and the boatman hovers on. I lower the point till it touches the water. The boatman is instantly aroused ; it springs forward on the needle. The sense of touch through contact with the water stimulates the insect. It would not be so foolish as to dart upon a needle had vision been its guide. But it is easy to make still more certain that it is touch and not sioht which cjuides the boatmen to their prey. I stand a glass tumbler in a basin of water. I pour water into the tumbler until it reaches the same level as the fluid outside. I now place six boatmen in the basin and they swim about content. I throw them some insects ; the boatmen dart on them, plunge beneath the surface to drown and devour them. At a distance of six inches they feel the prey touch the water and dash forward to the capture. I now throw some insects into the tumbler. They fall on the water standing at the same level as the water in the basin. The boatmen are swimming outside ; the insects fall within the glass. The insects fall close to the boatmen, but the glass intervenes and the boatmen take no notice. I throw an insect into the orlass when the boatman is on the water outside not half an inch away, but it remains quite oblivious OBSERVATIONS ON INSECT LIFE 173 of anything that has occurred. The glass intercepts the surface vibrations of the water ; it cannot affect the boatman's vision. The boatman can well appre- ciate the direction from which the vibrations come. I approach one with a needle and touch the water with the point. The boatman is aroused but it does not act aimlessly ; it first turns about so as to face the point where the needle touches the water before makino- its unerring stroke. This tactile sense is exquisite. The boatman is not disturbed by vibrations other than surface tremors. It is not misled by the ripples of the wind. I tap the sides and bottom of the basin, but this will not excite the insect. Visible ripples may flow across the basin, but the boatman is not deceived, I will mention a more remarkable instance as a proof of the nicety of this tactile sense. I drop some fragments of cork into the basin, and the boatmen, feeling the vibrations, instantly spring upon them. I allow the same pieces of cork to strike the surface by floating up through the water from below, and the boatman takes no notice. In both cases the surface vibrations spread over the surface of the water. In one the contact is from above, in the other from below, and the boatmen can discriminate between them. It seems most probable that it is on one of the parts of the insect in contact with the surface of the water that the sensitive organs of touch will be developed. Those parts are the tarsi of the first two pairs of limbs and the tip of the abdomen. Now just at the base of the claws of the intermediate tarsi there is a specialized tuft of delicate hairs, and I have thought that these might have been the highly sensitive 174 A NATURALIST IN HIMALAYA organs of touch. These creatures possess, so far as I could see, no trace of antennse, and are therefore deprived of one organ very essential to insect life. The conjecture of course arises that to a land insect an antenna is a very necessary organ, but for a water insect the hairs on the tips of the tarsi can fulfil the function better since the detection of surface vibra- tions is so important to its life. When the insects left the land and sought an existence in the water the antennse underwent degeneration and the sensitive organ was developed elsewhere. Nor is it difficult to picture the organs in an intermediate state, when the antennae were degenerate and the sensitive hairs only partially developed. It is not unreasonable to believe that water insects attained their present mode of life in the pools and streams as a consequence of a gradual change from terrestrial to aquatic habits in remote ancestors that once lived upon the land. In this connection it is interesting to observe that these water-boatmen will occasionally scramble out of the pool to take a short walk along the bank, and when they do this, they revert to the normal insect posture ; they no longer move upon their backs, but walk about on their legs after the manner of their terrestrial ancestors. In the society of the streams and pools all the members live in continual conflict. I passed many evenings watching the incessant struggle for life. Not a cloud in the clear sky ; not the gentlest breeze ; not a sound in the mountains to disturb the tranquil scene. One would think that in these placid pools Nature was happy and at peace. But no. War and destruction reign everywhere in Nature. As I walk OBSERVATIONS ON INSECT LIFE 175 along- the margin of the pool, insects start up from the dried grass. Locusts tumble into the pool and are swallowed by greedy frogs lying in wait upon the surface. Smaller insects, in their efforts to escape, fall a prey to a shoal of water-bugs and are suffocated in the stream. Others, that escape the water, meet their enemies in the air. The larger kinds may be seized by insectivorous birds ; the robber-flies watch for intermediate forms, and the winged ants or tiny Diptera are pounced on by the clragon-flies that methodically work along the stream. Spiders that spin their snares across the pool live a life of continual carnage. They destroy and they are themselves destroyed. Insectivorous birds may spy them, or a spider may drop too far upon its filamentous thread and fall into the jaws of a ravenous frog, while down below in ambush amongst the green weeds are the patient crabs to whom the frogs themselves are prey. It is a merciless and cruel battle between all the inhabitants of the pool ; there is no rest from the continual warfare, no prospect of peace. To each occupant the little pool is a world and all the world is at war. A few fish occupied the streams, but I observed nothing of special interest in them. At the entrance to the valley, however, was a sacred tank, thronged with fish, so tame and so dependent on their owners that they must be considered as domesticated creatures. These fish are objects of veneration amongst the Hindu Pandits. They may not be captured, but I feel sure they are the common species of mahseer, Barbus tor. The fish grow to a large size and people the tank in such numbers that, were they 176 A NATURALIST IN HIMALAYA not artificially fed, only a fraction of them could survive. The Pandits care for them, feed them, protect them from injury, and, in return, derive a small livelihood by displaying to strangers, in the hope of reward, these living objects of their veneration. The introduction of the fish into the tank and the kind care taken of them by their owners has greatly changed the character of the fish. From a shy creature defying the angler's skill, it is transformed into an animal that regards man as its protector and support. So fearless have they become that, when the priest approaches the wall of the tank, the fish advance to meet him, and either take the food directly from his hand, or dash after the fragments, struggling and leaping in such a seething shoal that the placid water seems to boil within the tank. That a fish can recognize its keeper and advance to meet him, and that it can so change its mode of action as to appear to regard man no longer as an enemy but as a friend, seems to imply some degree of mentality and possibly a dim shadow of consciousness. It has always seemed to me remarkable how feeble is the manifestation of conscious life in the higher fishes which possess a nervous system of such comparatively advanced structure. The intensity of their emotions is clear. The anger of the males in sexual rivalry or their solicitude in parental love are the outbursts of glowing passions that demand no conscious effort for their fulfilment. But the fact that these creatures can so change their existence under unusual conditions as to hasten towards a being that before would terrify them, and to behave in his presence as though he were not an enemy but a OBSERVATIONS ON INSECT LIFE 177 friend, seems to suggest some glimmer of consciousness and perhaps a tiny gleam of reason. Next to the ants, no insects in the valley interested me more than the various kinds of bees and wasps with their many peculiar instincts. The widespread species, Vespa orientalis, that extends into Northern Africa and Southern Europe, was very common in the district. I sometimes watched a continual stream of these wasps, large, brown, ferocious-looking insects with bright yellow bands on their abdomens, passing backwards and forwards. Those passing in the one direction were laden with a rich store of provender, and those in the opposite direction were returning empty for a fresh load. It was a perfect picture of insect industry and labour. I once followed the living stream across the country. At length I found the nest in the wall of a neighbouring village, and from there I traced back for over a mile the line of busy workers and did not even then reach the furthest limits of their toil. Over the granite rocks, across the open plains, high above the village roofs and the waving fields of corn, the stream of insect labour moved in one continuous flow. What sense was guiding them in their unerring road ? What force impelled them in the same unswerving line, to chose a course direct, undeviating and headlong to their nest? It may have been the rocks and trees that were the landmarks on their route, but I greatly doubt it. To see a wasp sailing in an unerring flight high over a broad expanse of corn and shaping a course direct for its distant nest, was to feel that some other sense than sight impelled it, for to a wasp a rolling field of corn must be as trackless as a boundless ocean. N 178 A NATURALIST IN HIMALAYA Far and wide these wasps had scattered over the country. Wherever filth and refuse had accumulated there were the wasps to be seen searching every corner for a precious burden. Down the village street, exploring every nook and cranny in the foul bazars, boldly entering every shop, busy amongst the mules and camels of our transport and far around over the fertile fields, these industrious insects were engaged from morning to night in a continual search for plunder. Fragments of decomposing meat, decay- ing remnants of fish or anything of a sugary nature was enveloped in a swarm, torn into pieces by a hundred busy jaws and carried off to the nest. These wasps, at certain times, are the natural scavengers of the country. With the kites, the pariah dogs and the dung-rolling beetles, they help to cleanse the village of its refuse. At one place they had crowded round a dead pigeon. Nothing was left of the flesh but a few tough fragments on the wings which the wasps were unable to separate from the bases of the quills. They dragged about the feathers and the whole wings in the attempt to bite away the hard fibres, and one of them, unable to detach the flesh and unwilling to desert its provender, sailed away for the nest carrying in its tiny claws a large pinion almost five inches in length. It was amusing to watch the insect struggling in the air laden with this strange burden. The breeze seized the broad vane of the feather ; the wasp was wafted about by every wind and sometimes whirled around in circles in the air, yet it still struggled on, and at every interval of calm it renewed its efforts to make direct for the nest. All the changing and eddying breezes, OBSERVATIONS ON INSECT LIFE 179 though they turned the wasp about in every direction, could not confuse its guiding sense and turn it from the true road. I gave the wasps one of their own dead comrades. The cannibals rushed upon it. One seized the body in its claws and endeavoured to rise into the air, but, powerful as are the wings of these insects, they are unable to raise twice the body-weight, so the wasp had to cease its efforts. Then a companion appeared on the scene. One seized the dead comrade by the head, the other by the abdomen ; they both drove their strong mandibles into the thorax and soon divided the wasp just in front of the wings. The one grasped the head and made off straightway on its journey ; the other struggled with the larger share, rose twice, and again fell beneath the heavy weight, but, rising higher in the third effort, it at last took wing for the nest, to add the body of its dead companion to the food of the growing larvae. Vespa orientalis used to construct its nest in the mud walls or roofs of the village houses. Through a narrow aperture the wasps enter into a spacious chamber in which is suspended the papery comb with its rows of hexagonal cells, I noticed that this wasp was in the habit of ventilating its nest by creating a current of air with the rapid vibration of its wings. I observed two wasps stationed at the aperture of the nest fanning with all their strength. It seemed clear that their object was to direct a current of fresh cool air into the interior of the tunnel. These wasps also post a sentinel at the nest aperture. The sentry is most earnest in its duty. It challenges 180 A NATURALIST IN HIMALAYA each new arrival, possibly examines each burden as to its fitness for the store, or identifies each worker before it gives admission in order to prevent the intrusion of a stranger. Sometimes, as though in doubt, it pursues a worker into the interior of the nest. It pays less attention to the departing wasps ; it seems to care little whether they leave empty or carry a little load of earth from the interior of the tunnel. As one ant knows every other in the nest, so it may be that this sentinel knows all others in its own community, and is placed there to prevent a stranger from entering the precious store. Another species of wasp, Polistes hebrcBUs, adopted a method similar to that of Vespa of vibrating its wings to lower the temperature of its nest. A colony of these wasps had built a large nest in a rose tree close to the verandah of my bungalow. The nest consisted of a circular comb hanging from a central stem and built of a single layer of hexagonal cells, all closed above and with the open ends directed down- wards. I noticed that in their efforts to cool their larvae they acted much like the Vespa. The nest was so situated that, throughout almost the whole day, it was shaded from the sun by the surrounding trees ; but, in the early morning, the sun, while still low on the horizon, could peep below an overhanging shrub and fall on one margin of the nest. As a consequence the cells at this margin became uncomfortably warm and gave the wasps much trouble in their labours to keep them cool. It was instructive to watch a worker- wasp creeping about over the heated cells, testing each one with its sensitive antennae. As soon as it discovered a cell which it considered too warm for the OBSERVATIONS ON INSECT LIEE 181 contained larva, it would stand over the spot, violently vibrate its wings for a minute or two, and continue to repeat this remarkable process until the draught of air, thus produced, had sufficiently cooled the cell. I never saw workers cooling any part of the comb except that warmed by the early morning sun, nor did they ever fmd any necessity to do so once the sun had so risen in the heavens as to be no longer able to peep beneath the overhanging verdure. It was by means of the antennae that the wasp ap- peared to judge if the cell required cooling, so that I suspect that the antennae, in addition to other functions, also possess the sense of judging changes in temperature. This cooling of the cells by fanning is probably a satisfactory process. It is not a customary habit of Polistes, as the species seldom hangs its nest in a sunny place. We may perhaps regard it as an early stage in the evolution of that far more complex system by which relays of workers, all fanning in regular order, can ventilate with a fresh current of air the dark hive of the honey-bee. There is another slight resemblance between the Polistes and the honey-bee. Polistes loves to suspend its nest from the roofs of dark verandahs or the ceilings of disused rooms, yet it sometimes chooses to build in the shelter of a thick bush, or even on the branch of an exposed tree. The hive-bee also, especially the form known as Apis dorsata, has been known to build in the open when no hollow tree is to be found. It probably once possessed the habits of Polistes, some- times building on an exposed branch, but usually seeking a shady place ; and when now a European 182 A NATURALIST IN HIMALAYA honey-bee constructs its comb in the open air we perhaps see a relic of a more general ancestral habit when it once lived in a tropical clime. Another conspicuous member of the Vespidcc in the Western Himalaya is Vespa magnificat one of the largest and most powerful of the species. The queens, which fly about early in the season, are ferocious- looking insects ; they are almost an inch and a half in length, of a dark brown colour, with the base of the antenntE a bright orange, and the whole body covered in a silky golden pile. The point of interest in the life of this wasp is the habit it has of making depreda- tions on the hives of the honey-bees. I observed it attacking the swarm on different occasions. The honey-bees, Apis indie a, had settled in a hollow tree. The workers were busy entering and leaving the aperture, and there was an appearance of bustle and energy about the hive. Some of the workers were, as usual, creeping lazily about the opening as though they had no special duties to perform. Suddenly a queen of V. magnifica appeared in the vicinity of the nest. It hovered about the entrance giving utterance to an angry buzz. The workers feared the intruder ; at intervals one of them would dash at it in a vain and timid effort to drive the enemy away. But the Vcspa came in closer to the hive, and after some hesitation made a sudden swoop on one of the more sluggish workers, which it bore away in its jaws. In four minutes it again returned, seized another worker, and this time I distinctly saw it turn forward its abdomen to plunge its sting into the body of its prey. It then made off to a neighbouring branch, where the victim was devoured. A Vespa worker then appeared and OBSERVATIONS ON INSPXT LIFE 183 joined in the act of plunder. It did not attack with the same gallantry as the queen ; it was very unwilling to approach the hive, and only at a favourable moment would it dart in upon its prey. On another occasion I saw the Vespa plundering the compact swarm. The bees had gathered into a seething globular mass. They hung suspended from a branch, a trembling globe replete with danger and quivering with angry life. A few workers were leaving ; many more were arriving to join the clustered swarm. A Vespa magnijica appeared. It hovered about the black heaving mass, but it feared to come too close. It never dared to extract a worker from the swarm. It awaited its chance a little distance away and occasionally fell upon a vagrant worker as it was about to leave or join the throng. The Vespa magnijica is therefore a plundering and rapacious species, and I have no doubt, from the way these wasps systematically remove victim after victim, that they must work great destruction amongst the hives of the Himalayan honey-bees. Wasps and bees occasionally mimic other insects to which they bear a close resemblance both in structure and habits. Some of the digger-wasps are very simi- lar in appearance to certain ants. Amongst a number of ants belonging to the species Camponotus cojnpressus that were seeking for aphides on a rose bush I noticed a little Pompllid wasp running eagerly about. It resembled the ants even to minute points in its anatom- ical structure ; it moved with the same jerky gait ; it vibrated its antennae in a similar manner and system- atically searched each leaf just as though it was a, Carnponotus ant, 18 1 A NATURALIST IN HIMALAYA This close resemblance between insects of different orders has been observed in different parts of the globe. Another instance specially struck me, though it has frequently been noticed before, of the extra- ordinary similarity in the external appearance of the flies, Bornbyliiis, to the humble-bees, Bombus. The common humble-bee in these hills was Bombus tunicatus. It used to frequent the wooded slopes at an altitude of 8000 feet, and there it busied itself amongst the flowers that blossom above the under- growth. Now the coloration of this bee is very distinctive. It displays a black shining head, a thorax hoary white with a black band between the wings, an abdomen with three successive bars of white and black and red. We look to the fly and see an identical coloration : the same black head ; the same pubes- cent thorax with its hoary fur and intermediate band of black ; the same abdomen with its bars in the same order, white and black and red. In fact the insects are marked from head to tail with seven transverse bands, and these bands are identical in each. Such superficial resemblance is remarkable. For it is evident not only in the exact shade of coloration, but in the width of each band, and the general scheme of decoration is identical in both. Similarly it is with the shape and build of the insects and the buzzing sounds that they produce. They occupy the same stations and feed on the same flowers. If defence is gained by this resemblance it must be all in favour of the fly. And this would seem in accordance with the principles of mimicry. For the fly is the more defenceless of the two ; it exists in much fewer numbers than the bee ; it is a rnore wary and active OBSERVATIONS ON INSECT LIFE 185 insect, tending to keep more in the shady under- growth and less on the open flowers. Humble-bees are well known to play an important part in the fertilization of many flowers. It was instructive to watch the untiring industry with which they sought the nectar from a pretty little blue blossom, the Strobilanthus dalhousianus. In this act they showed a good example of the variability of instinct, how different individuals of the same species will each employ its own method in order to attain a common end. For some of the bees were in the habit of pushing their way into the interior of the funnel- shaped blossoms in order to reach the nectar, while others had learnt to adopt the simpler plan of drilling a hole with their mandibles through the base of the corolla and in this way secured the nectar by a shorter route. Now this variation in the instinct appears to be very fixed in different individuals, each always acting in its own peculiar way ; for I once watched a pair of bees belonging to the species Bombus hcEmor- rhoidalis actively engaged upon a profusion of Strobi- lanthus, and of the two, one always gained its end by perforating the corolla, while the other persisted in the more laborious task of pushing its way into the interior of the flowers. There is another point worth notice in this little observation. I suppose it is reasonable to assume that it was the original habit of the humble-bees to come direct to the mouth of the blossom in the same way as other insects and to reach the nectar by the obvious route. The plan of cutting a hole through the corolla is a new device, a later instinct developed in order to give the b^e? less trouble, to save more of 186 A NATURALIST IN HIMALAYA their valuable time, and perhaps to allow them to secure the nectar from those blossoms which are too narrow to permit their entering within. The behaviour of the bees themselves supplies some evidence to show that this supposition is true. For if one of these perforating bees is watched with a little care, it will be seen that it does not go direct to the place where it intends to perforate, but rather reaches the base of the corolla by an indirect route. It always goes first to the open mouth of the flower, then runs down along the outside of the corolla until it reaches the point where it is accustomed to cut through. Why does it act in this way ? Why does not the bee go direct to the base of the corolla ? Why does it go first to the mouth of the flower ? The procedure seems a useless one, and certainly involves the bee in addi- tional labour and wastes its precious time. I think there is something to be learnt from the act. I believe we see in it a relic of the past, a trace of that older instinct when the bee was accustomed to sip the nectar by entering the interior of the flower. The bee had then of course to go first to the mouth of the blossom, then crawl down the inside of the funnel in order to reach the nectar. But now, although the instinct has partly changed and many bees secure their nectar by cutting through the base of the petals, yet the relic of the older instinct still remains ; the bees still persist in going first to the mouth of the blossom and then run down the outside of the funnel, and at length reach the point of perforation by a longer and indirect route. The act is a kind of fossil instinct ; the useless remnant of what is gone. And it is in these relics of OBSERVATIONS ON INSECT LIFE 187 forgotten habits as it is in the fragments of now worth- less structures, that we can to-day review the past incidents and changes which have influenced the course of organic Hfe. Another plant visited by the humble-bees with untiring energy is the pretty little yellow balsam, Impatiens scabrida. Both the humble-bees, B. tuni- catus and B. hcEmorrhoidalis, used freely to fertilize this balsam. The size and form of the bell-shaped flowers are beautifully adjusted to that of the humble- bees. There is just sufficient room for the bee to squeeze itself into the interior of the bell beneath the overhanging anthers, and in so doing it covers the upper surface of its thorax with a coat of viscid pollen. When the flower first opens the pistil is enclosed within the compact bunch of stamens and is thus hidden from view, but later, when the petals begin to shrivel, the stamens fall away so as to expose the mature stigma and bring it in contact with the pollen-stained thorax of every fertilizing bee. As in the case of the Strobilantktis, the bees secure their nectar from this flower also by two methods, either by perforating the corolla or by pushing down into the interior of the bell. It is an advantage to the plant if the bees enter the blossom, since in this way they distribute the pollen and fertilize other flowers. It is an advantage to the bees if they perforate the corolla, as by this means they secure the nectar by an easier and shorter route. But this must be only a temporary gain ; in the end they would also be the losers, since they would be deprived of their nectar by fertilizing no flowers. Thus there is a ceaseless competition between the 188 A NATURALIST IN HIMALAYA plant and the insect. The balsam is always striving to adjust its blossoms to the size and shape of the fertilizing bee. If the bell grows too wide, then the bees will be able to enter without touching the anthers ; if the bell grows too narrow, then the bees cannot enter at all, and they will then adopt the new plan of perforating the base of the petals. In either case the plant will be the loser, as the bees will fail to fertilize the flowers. The competition is no doubt incessant, and only those plants bearing flowers of suitable size and shape will be able ultimately to survive. Never- theless, the plant must meet with great success in the struggle, since it is a dominant species, and its beauty is now spread and may be still further spreading over the wooded slopes of the Western Himalaya. In this plan of perforating the base of the corolla the hive-bee seems to be lacking in the instinct so well performed by the less social humble-bee. It is amusing to watch the hive-bee in its earnest efforts to secure the nectar from some tubular blossom too narrow to permit its entering within. It eagerly examines the outside of the tube ; it explores with its antennae the base of the corolla in the hope of finding a way in. It sometimes meets with a blossom about to fall from the parent stem, and in this way discovers a natural aperture through which it can insert its tongue, or it may happen to alight on a hole previ- ously cut by a humble-bee. It knows well the exact spot where the nectar lies, but what it seems quite unable to do is to cut an aperture for itself. It cer- tainly seemed a little strange that a species endowed with such mental attributes as the hive-bee, in which the social instincts are so highly developed and to OBSERVATIONS ON INSECT LIFE 189 which the faculty of inteHigence has so often been ascribed, should fail in a simple device that has long since been discovered by a number of the less gifted humble-bees. Towards the end of May a number of small leaf- cutting- bees, belonging to the species Megachile ccphalotes, determined to construct their nests in my bungalow. They selected the holes that once held the screws for the hinges of an old doorway. I often used to watch them coming during the heat of the day carrying their burdens to the screw-holes and lining their tunnels with a layer of leaves. It was interest- ing to observe how the bee used to take the edge of the leaf between its jaws and work all round the margin licking it with its long tongue, and covering the edge with a sticky secretion to make it adhere firmly to the underlying leaves. It reminded one of a human being licking the edge of an envelope in order to seal it down over a letter. And the resem- blance was more complete, for the bee would often press down the gummed edge with its mandibles and, I think sometimes, with the front of its head, just as a man presses down the edge of the envelope with the fingers in order to make it firmly stick. The mud-wasps of the genus Bzcuienes are well known in India. They commonly enter houses and construct their mud nests ag-ainst the walls or furniture of the room, and provision the cells with caterpillars as food for the larvae. A large species, E. dimi- diatipennis, used to make a flat nest of smooth clay on the wall of my bedroom. It was composed of mud without the trace of a pebble. One evening I discovered that a species of mud-wasp had constructed 190 A NATURALIST IN HIMALAYA its nest beneath an overhanging ledge on the face of a chff composed of a fine conglomerate. Now a nest of smooth, pale mud lying against the stones of this cliff would be very conspicuous, and I felt sure that the wasp must have understood this. For it had covered the whole surface of its nest with pebbles so that it was very difficult to differentiate the nest from the underlying conglomerate. The rounded stones, with which the wasp had studded its nest, were compara- tively large, many over a quarter of an inch in diameter, and it seemed surprising that the insect could carry so substantial a load. I was deliohted when I discovered this little nest of pebbles, for I felt certain that I was looking at a beautiful instance of harmonization, so invisible did the nest become by blending with the conglomerate cliff I wrote in my journal that "this was one of the prettiest examples that I had seen in the life of insects of a plastic instinct employed to so useful a purpose, for I have no doubt that it was a gain to the species to render its nest invisible through harmony with its surroundings by covering it with a layer of the same little water-worn pebbles that went to build up the conglomerate cliff" But I was making a grievous error. These nests were not common, and for some weeks I could find no others than those on the conglomerate cliff, until one day I discovered a nest of four cells implanted on a smooth slab of slate. I was surprised, for I had felt almost convinced that the covering of pebbles was an example of a wonderful protective instinct and that a wasp constructed a nest of pebbles only against a pebbly cliff, yet, there before me was a nest studded OBSERVATIONS ON INSECT LIFE 191 with brown and white pebbles standing out against a background of purple slate in so prominent a manner that any one might see it. Had the wasp intelligently attempted to construct a conspicuous nest it could scarcely have been more successful. I was disappointed at finding that the pretty example of harmonization was but a myth, but 1 had received an excellent lesson in the dano-er of arrivino- at a conclusion without careful and repeated observations. I found the little digger-wasp, Arnmophila} very active at the end of June in the open glades of the forest at an altitude of 8000 feet. It is an insect of wide altitudinal distribution and ascends to at least 11,000 feet. It is a slender black species somewhat under an inch in length, with the sides clothed in a silvery pile and the front two-thirds of the abdomen coloured in a shining red. On a patch of short grass the wasp was incessantly digging, hunting for cater- pillars, or feeding on the sweet flowers. It was amusing to watch its untiring industry in the excavation of its tunnels, thrusting out the soil in spouts of sand, sweeping it backwards with its fore legs and dislodging the larger fragments with its mandibles. The marvellous instincts of these wasps have been displayed in the minute and accurate observations of Fabre. The Anwiophila captures caterpillars, paralyzes them by a succession of stings into the different segments of the body, crushes their heads between its mandibles and then drao^s them off to * Mr. Bainbrigge Fletcher, who kindly examined my specimens of this wasp, tells me that an exactly similar specimen from Abbottabad has been returned to Pusa named by Mr. R. E. Turner of the J^ritish Museum as Psavunophila iydei, but that the species is an Ammophila according to Bingham's diagnosis of the genus. 192 A NATURALIST IN HIMALAYA a previously prepared tunnel in the ground. After lodging the victim in the blind end of the tunnel, the wasp lays an egg upon it, then seals the entrance, disappears and comes no more to the nest. I will here mention a few illustrations of the blind- ness of instinct displayed by this species. The first problem was : How will the wasp behave if, when in search for plunder, it discovers, not a virile prey, but a caterpillar already paralyzed with the head already crushed.-^ Will the wasp despise such prey, or will it recognize that the caterpillar being paralyzed, there is no need to repeat the process, that much of its work has been already done, and that nothing now remains but to drag away the larva and to bury it ? I unearthed a caterpillar from a wasp's nest. It lay motionless, paralyzed from the repeated stings of its captor. On its left side, distant from its head by one-third of its length, was attached the oval whitish Ggg. I placed the exhumed caterpillar before a wasp that was running about in search of prey. The wasp rushed on it. Never had it found such a morsel as this. Here was a prey that made no struggle to escape, that needed no sting to overpower it. Yet the wasp could not recognize this. It seized the passive larva in its jaws and legs, pierced it eight separate times with its sting, and finally crushed the head between its jaws. All was labour lost. The caterpillar had hours before been paralyzed by a previous wasp ; its head macerated by other jaws. But the wasp could not appreciate this. That the caterpillar made no resistance had no influence on the wasp. Struggle or no struggle, the force of instinct OBSERVATIONS ON INSECT LIFE 193 must be fulfilled. The caterpillar cannot be removed until sting and jaw have done their work. The paralyzed larva must be again paralyzed, the crushed head must be again crushed before the next step in the instinctive round can follow and the caterpillar can be draoored into the cell. The closure of the nest supplies a second instance of the utter folly of the insect when, through any interference, the instinctive round is broken. A caterpillar has been carried to the nest, dragged below, an egg has been laid and the wasp is now industriously engaged in sealing up the tunnel. First it spreads a roof over the buried chamber to provide a safe nest for the growing egg. For this it selects what is suitable from the soil around. A bulky pebble or a few flat larainai of slate serve the purpose and are pushed down into the pit. The wasp follows, moulds them into place by the pressure of her head until the cell is closed. The roof secure, any material serves to block the tunnel. Surrounding debris, dust or sand or pebble, is shuffled indiscriminately down the passage. More is poured in ; everything is swept backward into the pit. All it needs is to be pressed tight ; the tunnel wall must be a consolidated, not a crumbling structure. Down goes the insect's head, the legs clutch the sides of the tunnel, the wings vibrate, and, with the vertex as a ram and all the strength of the body as a driving force, the loose particles of crumbling earth are compressed into a solid mass. Again the debris is poured in, again the process of consolidation follows. The stoppage of the tunnel is half complete and the wasp rests. It flies off to a neio^hbourincr bank of flowers. It will O 194 A NATURALIST IN HIMALAYA feed for a minute, then resume its work. For one half the tunnel remains to be filled in. Now is the time to expose the insect's folly. I open the tunnel, lay bare the cell, extract the cater- pillar with the white elliptical egg adherent to one side. I lay the caterpillar right across the entrance of the ruined tunnel that leads to the pillaged cell. The problem is : What will the wasp do when she returns to her labour ? She left behind a tunnel, the inner half walled, the outer half not yet complete. She returns to find another picture. Facing her tunnel is the larva and Qgg, the object of all her toil ; within is the ruin of her work ; her solid wall is no more ; at the end of her tunnel is a broken and an empty cell. Surely she will recognize all this ; she will either replace the caterpillar and repair the damage or desert the hopeless ruin. But no. The wasp returns. She approaches the tunnel as though oblivious of any change. She treads on the caterpillar lying at the entrance ; she stands astride of her own egg, but sees nor cares nothing for it. She reaches the mouth of the tunnel. Before her lies desolation and ruin ; within is the pillaged cell ; but to the wasp all is in good order. She has returned for one object, to seal the outer half of her tunnel. To the fulfilment of that duty she is now so abject a slave that she is impelled to do it whether she wills it or no. So she continues where she left off. She shuffles earth into the ruined tunnel, pours dust into the empty cell, discards the exposed cater- pillar, in fact resumes her labour just as if nothing- had happened and cell and tunnel were in perfect order. OBSERVATIONS ON INSECT LIFE 195 Futile is such toil, and every sign of its futility lies patent before the wasp. But the wasp sees it not. What should be hidden lies exposed ; what should be filled lies empty ; what should be a solid mass lies a crumbling ruin ; but to the wasp all is well. She has returned to seal the entrance and, ruin or no ruin, seal the entrance she will. Instinct is blind. It has no concern in the why or how it acts. What it does it must do, and it can do naught else. Every link in its chain of action must be forged no matter how worthless the bond. CHAPTER XI BUTTERFLIES, MOTHS AND CICADAS Swallow-tails of Hazara — Sexual display — Protective coloration in butter- flies— Butterflies resembling leaves — Protectively-coloured moths — Enemies of butterflies and moths — Instinctive fear of enemies — Rainy season in Hazara — Habits and musical organs of Cicada. I HAVE a few observations to make on the Lepi- doptera. The butterflies of the valley were not specially attractive, but many beautiful kinds fluttered through the higher woods. In the open glades were bright-coloured species that love the sunlight. Here different species of Colzas, Pie7'is, Vmiessa, Argynnis either hasten from flower to flower or collect into quivering groups over the moist patches on the ground. In the shade of the trees are more sombre species, chiefly of Satyrus and Ypthima. For a few weeks the woods are thronged with species. Every glade is gay with life. Then, as if by magic, all in a few days disappear and new forms take their place. Swallow-tails of most beautiful colour fly overhead or dart swiftly down the slope. The widespread Papilio mac/iaou occasionally appears. Its soft yellow wings are veined and bordered with a dense black, marked above with yellow crescents and adorned beneath with spots of pink and blue. From the hot plains even to the line of permanent snow this butter- fly may anywhere be found ; but nowhere does its 196 BUTTERFLIES, MOTHS AND CICADAS 197 beauty seem more fitted to its life than amongst the subtropical flowers. More striking is Papilio philo- xenus, a large black species, moving with heavy flight and hoverincr like a hummingf-bird before a flower. On its hind wings are bright and crimson bands handsomely displayed as it hangs on the blossoms of the chestnut. A smaller, but equally lovely species, is P. cloatit/uts, a swift and active swallow-tail sweeping hither and thither above the viburnum, showing its delicate green transparent wings surrounded by a jet-black border, like windows in a dark frame. Most beautiful of all is P. polyctor with an expanse of over four inches. It is a dark brown colour, covered in scales of golden green ; its hind wings stamped with a patch of brilliant blue and a border of pale red crescents beyond a band of velvet black. All this lovely play of colour flashes in a moment before the eye as it hangs fluttering upon a flower. Sometimes these beautiful polyctors collect into groups of ten or twelve about some patch of moisture on the ground. There they rest with quivering wings or rise above the pool in short amorous flights, where they dance and hover in the air. A gleam of green and gold and blue flashes from their gaudy wings ; new colours shine out at every movement and in every changing light. It is the most beautiful vision of insect beauty to be seen in the Western Himalaya. Butterflies often display great energy under the influence of sexual excitement. Junonia orithya is a very common and beautiful species with brilliant blue wings. While the female is seated on a flower the male circles round her in hovering flight with his wings quivering so violently that he might be a hawk-moth 198 A NATURALIST IN HIMALAYA hovering before a flower. At intervals he ceases, sinks down to the female, strokes her with his antennce and then rises again to recommence his whirling flight in ever swifter circles. The common brimstone butterfly, Goneptevyx rhainni, another very conspicuous and attractive species, is equally eager at its court- ship. In amorous circles the male hovers round the female and strokes her at intervals with his winor-s. It O may be worth mentioning that both these butterflies, in which the sexual enthusiasm was specially intense, were very conspicuous and brightly coloured ; in both the numbers of the males predominated over the females, and in both the male was the more brilliantly coloured of the two. The subject of protective coloration is perhaps hardly worth discussion, since so many examples of the great principle have been collected in every part of the world. But I feel inclined to mention a few instances which specially attracted me in connection with the Lepidoptera. A peculiar butterfly, Nytha parisatis, one of that large family, the Nymphalidce, was common at 4000 feet. It is a dark brown species with a light bluish marcrin alongr the termen of the winc;^s. The under surface is of a paler hue, streaked with white and ornamented with black ocelli. Now this butterfly haunts the hills of slate. It is in the habit of settling on the bare rock, usually in dark crevices or beneath overhanging ledges, where its brown wings harmonize well with the similarly coloured slates. On ascending to 6000 and 7000 feet we meet with two other species possessed of a similar habit, Satyriis schak^^a and Aulocera brahminus. These are also dull-coloured BUTTERFLIES, MOTHS AND CICADAS 190 butterflies of the same family and they likewise seek protection against the dark rock, but they are not so successful in this as is Nytha parisatis. Many butterflies bear a close resemblance to the leaves of certain trees and no doubt gain protection thereby. A little butterfly known as Libythea myrrha was certainly a member of this group. This species has its upper surface of a rich brown colour marked with some blotches and streaks of yellow. But when it alights it rests with its wings tightly closed, and then the appearance of the insect both in shape and colour is very similar to a dried leaf. It is a butterfly of swift and erratic flight and is in the habit of settling on the smaller branches of the trees, where it must often escape observation by virtue of its leaf-like form. Indeed I have little doubt that the possession of protective shape and colour must be of distinct ad- vantage to this species, since it is one of the few butterflies that I have ever seen attacked by insec- tivorous birds. My remarks on protective coloration would be very incomplete if I made no mention of that most striking example of leaf butterflies the Kalliina inachns. This butterfly is almost classical, and was brought into special prominence by the researches of Dr. Wallace in Malay. Even in the dried state when preserved in a museum there can be no mistaking the fact that in this insect the principle of protective coloration has been developed to the most refined degree. We see it in the shape, the size, the outline of the wings, which is clearly that of the forest foliage ; we see it in their dull brown colour which resembles that of the forest leaves ;• on the wings we see the pair of tails 200 A NATURALIST IN HIMALAYA that mark the stem, the pointed tip that marks the apex, the central band that marks the midrib, and the lines that mark the veining of the leaf. At the tips we see the clear white spot that looks like an insect- boring, and beneath is the profuse and varied mottling such as stains the surface of the fungus-covered leaves. But the Kallinia must be seen in its natural habitat in order to appreciate the full value of this wonderful protective scheme. We wander through some shady glen where the dense foliage is spread out above and the leaves of the oak are strewn thickly over the ground. Suddenly a brown fluttering object rises up before us. It looks like a withered leaf that has been wafted upward by a gentle breeze. It flutters on. We follow it with the eye. Suddenly a flash of yellow appears and we know it to be a Kallirna. On it goes in a swift confusing flight. It darts and dances in the air. Then in an instant it seems to turn on itself; it disappears ; it has alighted head downward on a bush ; its wings have come sharp together and it is trans- formed into a leaf. Sometimes in these same haunts we come upon another very similar and equally remarkable form, the Melanitis. It resembles the withered leaves as closely as does the Kalliina. Its flight is equally swift and erratic, but there is no patch of yellow on its wings and it never alights on the bushes, but chooses rather the dead leaves that lie strewn about the ground. There is no doubt that these two butterflies when seen in their natural habitat make a deep impression on the observant mind. It is not only the close anatomical resemblance between the butterflies and the BUTTERFLIES, MOTHS AND CICADAS 201 withered leaves, but the way they cling to their leafy haunts, their swift and zigzag flight, the way they suddenly burst into view and then as if by magic instantaneously disappear, must place the Kaliima and the Mclanitis amongst the most perfect examples of protective coloration that can anywhere be seen. I am not certain if the butterfly Dophla patala actually occurs within the limits of Hazara, but I have seen it in the Himalaya a little further to the east. It is a butterfly of some four inches in expanse, of much the same size and shape as the Kaliima. Its upper surface is of a rich green marked with patches of pale yellow, and its form is such that the colour, shape and outline of the wings closely resemble the mature green leaves that grow on the forest trees. The cilia that border the edge of the wings are marked with spots alternately light and dark, and this has the effect of giving the outline of the wings some resemblance to the crenated margin of a leaf. It might be thought that the yellow patch on the surface of the wings would have served to destroy the protective scheme, but this is not the case, since many of the forest leaves are marked with similar spots of yellow which indicate where the green tissue of the leaf is first passing to decay. The Dophla is a butterfly of rapid and irregular flight. It som.etimes settles on the ground or on the bark of a tree, in which places it is fairly conspicuous ; but its favoured haunts are the smaller branches, where it settles amidst the green leaves. It is there well concealed by its protective colours. It always alights with outstretched wings, as it is the upper surface that is coloured a protective green, and it has also the habit of slightly raising and lowering the 202 A NATURALIST IN HIMALAYA tips of its wings so as to give them the appearance of a pair of leaves moved gently by the wind. It is instructive to contrast the Dophla in its resemblance to the green leaf with such a form as the Mclanitis which resembles the leaves after they are fallen and dry. The Dophla is coloured a rich green to blend with the fresh foliage, the Melanitis is a dull brown in harmony with the scattered leaves ; the Dophla alights where it is lost upon the branches, the Melanitis seeks concealment on the leaf-strewn ground ; the Dophla rests with wide-open wings as it is its upper surface that is protectively displayed, the Melanitis alights with wings tightly closed for beneath is its protective scheme ; the wings of the Dophla are even and entire and so are the green healthy leaves, the wings of the Melanitis are ragged and torn and such is the scattered foliage in all stages of decay ; all the Dophla are much alike and such is the harmony in the mature leaves, in the Melanitis all differ and so do the littered fragments that lie everywhere beneath the trees ; the Dophla when it settles displays a pair of wide-open wings and so also is the growing foliage placed in pairs upon the stem, the Melanitis brings its wings tightly together so as to appear to have only one and thus blends with the multitude of single leaves that lie scattered broadcast on the ground. Such is the contrast between the Dophla and the Melanitis in their hard struggle for life. Each is secure in its own habitat ; each is perfectly adapted to the special nature of its own haunts. We can see all this in the dead insect, in its structure, its colour, its size and shape, but we must see each in its accustomed haunts, we must watch each select its own special BUTTERFLIES, MOTHS AND CICADAS 203 habitat, each aHght in its own pecuHar way, before we can appreciate how closely function is interwoven with structure and both with the protective scheme. More numerous and undoubted examples of pro- tective coloration are to be found in the suborder of moths. The place to seek them is in some shady glen where only a rare shaft of light gleams in between the trees and where no intruder enters to disturb their daylight haunts. They love the silent gloom where the long ferns droop down about the rocks, where the pale grey lichen clings about the trunks and the moss in tufted sprays hangs pendent from the oaks. Here they gather for the day amidst the dark and dripping foliage, where not a sound is heard to break the silence but the shrill noise of the cicada or the rumble of some distant stream. Many different kinds occur, each suitably adapted to the special nature of its own abode. Gnophus acciptraria is a dull grey-coloured moth nearly three inches in expanse, mottled with brown and with darker patches near the tips of the wings. This species was frequently seen between 7000 and 8000 feet, where it used to haunt the limestone cliffs and harmonized in a most perfect manner with the mottled colour of the stone. It is an insect of fairly strong flight and moves about after dark, at which time it is often attracted to the glare of an artificial light. In open places it is more uncommon ; but in a dark glen, where the trees drip with moisture and the bosses of limestone project through the decaying soil, this species will almost certainly be found. It seldom alights anywhere except on a grey block of limestone, usually in some dim recess where it clings head downwards with outstretched wings 204 A NATURALIST IN HIMALAYA pressed closely against the rock, and so carefully con- cealed that it can be detected only by the sharpest eye. It is an excellent example of a protectively coloured species that blends with a grey weathered stone. In marked contradistinction to the Gnophus is another nocturnal moth, Boarmia admissai'ia, a smaller species about two inches in expanse, with brown wings streaked at intervals with bands of black. This moth would gain no protection on the light-coloured lime- stone, so it resorts to the trunks of the trees. It spends the day attached to the bark of the pine, cherry, sycamore, silver fir and other forest trees. Its pattern of coloration bears the very closest resem- blance to the bark on which it rests, and makes it a difficult insect to discover until it flies out into the air. These two moths, the Gftopkus and the Boaruiia, cannot but arouse interest in the principles of pro- tective coloration, so perfectly adapted is each to the nature of its haunts, the one to the cliffs, the other to the trees, and each keeps so exclusively to its own respective habitat. Another little point of interest was that the different species of Boarmia did not necessarily seek protection in the same haunts. For instance, B oar 7nia granit aria was a smaller and greyish-coloured species, and it used to rest by day not upon the trees but on the slabs of limestone, with which it harmonized very well. Like the other species, it flies by night and often comes about a lamp. The colouring of its under surface is a little conspicuous, but this is of no disadvantage since it rests with wings outstretched and pressed firmly against the stone. BUTTERFLIES, MOTHS AND CICADAS 205 Another of these protectively-coloured moths was Gnophus variegata, a much smaller and lighter-coloured species mottled with a yellowish or pinkish tinge which harmonized fairly well with the hue of the mountain limestone. Its colours did not blend quite so accu- rately as was seen in some of the other species, unless it happened to alight on a specially suitable patch of stone. And we should remember that this limestone is marked with many streaks and patches, tinted with numerous shades of colour, clothed with different kinds of fungi, all of which so vary its surface as to fit it for the concealment of a number of distinct and varied species. Anonychia rosU-ifera was another very common species. It was a pretty little grey moth with a brown angulated pattern on the upper surface of the wings. It took refuge on the dark shales and I seldom saw it on the limestone. It does not harmonize so well as some of the previous species, and it seemed to prefer a somewhat lower altitude of 6000 to 7000 feet. There was also another little moth that sought the limestone, the name of which I did not determine. It was of a uniform grey colour and harmonized ex- ceptionally well with the weathered areas of the stone. This species seemed to rely even more than the others on its close resemblance to its environment, for I found that it was less liable to take alarm and less inclined to leave its shelter than any of the previous species. Abraxas sylvata was still another of the Hazara moths that possessed the habit of alighting on the crags of limestone. It is a white insect, with its fragile wings studded over with patches and spots of grey. This species harmonized fairly well with the stones, though any one seeing the insect in a museum would 20G A NATURALIST IN HIMALAYA scarcely have thought so. Harmony must be its main protection, but I was interested to observe that one which I took in a net remained perfectly motionless and shammed death. It has thus recourse to another method of eluding its enemies, and this is the only instance, with the exception of that widespread moth Deiopia pulchella, that has come to my notice of the strange practice of shamming death amongst this large division of the Lepidoptera. I have mentioned fourteen species of the butterflies and moths which frequent this valley, all of which would seem to be preserved because they resemble those structures on which they are accustomed to alight. Some seek protection amongst the leaves, others on the shales, others on the limestones, still others on the trunks of the forest trees, and the colour of each is beautifully adapted to the nature of its resort. I have been asked if these moths deliberately select the objects on which they alight with the conscious intention of seeking concealment. But this cannot be for a moment admitted. The moths have through generations gradually adapted themselves to those habitats where they would naturally find the greatest security. Those which tended to roam into other areas would soon be destroyed, and only the individuals which kept to those places that they resembled would ultimately survive. The GnopJms alights on the limestone, but it knows not why. On most occasions it closely resembles the rock on which it rests, but the moth does not understand this ; indeed I have watched it settle on a patch of dark shale and on an iron-stained slab of limestone where it was really conspicuous, but at the same time perfectly content. BUTTERFLIES, MOTHS AND CICADAS 207 It knew nothing of its colours and was quite satisfied when it settled on a stone. Similarly have I seen a Boarmia alight on a portion of a tree where the inner wood had been exposed by the woodcutters ; but the moth did not appreciate the fact that its dark wings were highly conspicuous against the white and splintered wood ; its instinct was to alight on wood ; it had satisfied that instinct and seemed contented with its choice. These moths know nothing of their wonderful protective scheme. Instinct tells one that it must spread itself against a stone, another that it must seek the trunk of a tree, but as to why it should do so it knows no more than why it unfolds itself from a grub. Protective coloration is developed to a much higher degree in moths than in butterflies ; and the reason of this is very obvious to any one who has taken much notice of their habits. Butterflies are seldom attacked by birds, while moths form a tasty morsel. If moths moved about by day in the same way as butterflies we should see them being continually devoured by a host of insectivorous enemies. It is only when they are occasionally disturbed that birds have an opportunity of darting on them in the air, and we seldom see those occasions when they are sought out and captured on the bark of the trees. I have records of warblers, robins, chats, flycatchers and woodpeckers from time to time devouring moths, and I have no doubt that they are far more persistently preyed on than the conspicuous but nauseous butterflies. Butterflies have few enemies, probably in conse- quence of their being distasteful to insectivorous animals. During seven years' observation in the East I have witnessed an attack of birds on butterflies only 208 A NATURALIST IN HIMALAYA in the case of three species. I have seen the large bee-eater, Merops persicus, hawk systematically and with destructive effect amongst numbers of the painted lady. I have already mentioned an attack made by a bulbul on a Libythea, but this butterfly is protectively coloured and looks very like a moth. The third instance was on the part of the paradise flycatcher, though this bird did not seem to be very eager, since it failed to secure its prey. I have no doubt about the fact that only on rare occasions do butterflies fall a victim to birds. Nevertheless, they show an instinctive fear of the few species that attack them. The Libythea hurls itself to the ground and there shams death ; the painted ladies are thrown into wild confusion before the assault of a flock of bee-eaters. When the bird dashes on the butterfly, the latter recognizes its clanger and swerves to one side. It then darts to the ground in a zigzag course, while the bird falls on it and often misses it again and again. I have seen four bee-eaters in succession fail to capture a butterfly that was fully aware of its danger. Any one who has seen birds hiding in the trees or scattering away for shelter in the undergrowth when a hawk appears in the vicinity ; any one who has watched worms emercje from the earth before the advance of a hidden mole, will feel satisfied that animals have an instinctive fear of their enemies. This is a fact in nature. It might have been thought an obvious truth that could be seen in operation on every side throuorhout the endless battle of life. But instances are not so very common. I think most creatures meet their end oblivious of the dangers that confront them. It is not unusual in India to see young chickens BUTTERFLIES, MOTHS AND CICADAS 209 hurry away for shelter at the sound of the angry caw of a crow. Doves will most savagely attack crows ; drongos will throw themselves ferociously on kites when they approach unpleasantly close to the nests. I will mention some less general instances. On a laro-e shallow lake I watched flocks of coots dash hurriedly from the shore into the water whenever a marsh harrier came sailing overhead. The appearance of the harrier filled them with intense alarm ; they all broke into wild commotion, made headlong for the water, which resounded with the splashing and the flapping of their wings. They fully understood that the harrier could swoop on them while on the land, but that they were in safety on the water. I have seen fishes in a river dash from the shallows into the deeper parts whenever a pied kingfisher happened to hover above them. In the rainy season the frogs of this valley were in the habit of congregating along the banks of the streams close to the brink of the water. Whenever a kingfisher or a heron would fly gently down the stream, then all the frogs used to spring headlono- into the water and dive down into the mud. Nothino- filled these froos with such alarm as the sioht of an approaching heron. Thus many creatures recognize their enemies and understand the dangers that they run ; but to others the end is swift and sudden and they know not how it comes. In the months of July and August the shrill noise of the Cicada rings loudly through the forest. The rainy season has then set in and vegetable life on every side springs into luxuriant growth. Fresh green grass covers every wooded slope ; on the alpine 210 A NATURALIST IN HIMALAYA pastures flowers of most vivid hue appear ; every bank is carpeted with soft moss and from every nook the varied ferns hang down their graceful fronds. Thick clouds collect about the dripping trees and spread over hill and valley in their strange inconstant shapes. It is often a remarkable siijht to look down from a moun- tain ridge on to the fleecy clouds that congregate below. We watch a thick mass of cumulus as it surges up the valley. It strikes against an opposing ridge and, like a sea breaking on the rocks, it pours down over the mountain side. Here the ascending currents of hot air oppose it ; they drive it again to the higher elevations ; they roll it back upon the ridge. The visible vapour again pours down. Conflict follows upon conflict ; the broken cumuli form and reform, scatter again over the sky, separate into ragged frag- ments of thin dissipating wisps. In varied forms they float about the valley, now thickening, now condensing, and always in a state of evanescent change. Some- times they obscure the hillside in a thin veil of translucent mist ; at other times they envelop it in a dense white mass that hides every feature from our view. Then, again, they may burst like a tempest on the cliffs or ascend through the air in a pillar of vapour like the smoke from a forest fire. At such a time as this the Cicada is heard on every side. Its shrill vibrating note resounds through the moist woods. At times all is silent ; then a single sound rings out from a point high up upon a tree ; a second soon adds to the music ; a host of others then join the chorus, until the whole forest trembles with the noise. The cicadas belong to the Homoptera, a suborder BUTTERFLIES, MOTHS AND CICADAS 211 of the bugs. The species common in the Hazara district was Oncotympana obmibila. Farther to the east in the Kangra valley was a second species of very similar appearance, Platylomia brevis. It was the latter species that I more carefully examined, but the following account of the musical apparatus is, I think, applicable to both. These cicadas are stoutly built insects about two inches in length. They are of a dark brown colour with a number of green markings, and support on either side a pair of beautiful trans- parent wings. The cicadas spend the day clinging motionless to the trunks of the trees. Their colours are a distinct advantage to them in this habitat, since they blend so closely with the bark that the insects are with difficulty seen. On sunny days they become a little restless, and in the open glades may be seen to take swift sallies into the air. They are widely dis- tributed in altitude and may be heard at all elevations, from the low-lying valleys up to a height of 10,000 feet. An occasional insect may be heard at any hour of the day, but it is at sunset or when the sky is darkened with impending rain that the woods vibrate most loudly with their shrill importunate cry. I will pass immediately to the musical organs of the cicada, and, since I have not been able to understand clearly the mechanism of the instrument from the descriptions that I have seen in works of natural history, I will here describe in a little detail how it seems to me that the music is produced. I must first enter on a few simple anatomical facts. I will mention five structures, each of which is in some way related to the production of the sound. A simple inspection of the under surface of a cicada 212 A NATURALIST IN HIMALAYA will reveal the presence of a pair of flat plates, each about three-quarters of an inch in length, that cover the anterior half of the under surface of the abdomen. These plates are known as the opercula. They are in reality prolongations backward of the hind segment of the thorax ; they lie one on either side of the middle line and are separated from the abdomen by a deep narrow fissure. Hidden away within the base of either operculum and stretched tightly across a hole in the side of the first abdominal segment is a tense white mem- , Shield. Drum Operculum. Fig. 7.' — Cicada {Platylomia brevis). Wings on near side removed to show position of musical organs. brane, a structure of great importance in the production of the sound. This is the tympanum or drum. In ap- pearance it reminds one somewhat of the organ with a similar name in the structure of the human ear. Im- mediately above and overhanging the drum is a curved plate that projects down from the first abdominal segment. This is obviously designed to protect the drum, and may be called the shield. These organs can be seen by a simple inspection (Fig. 7). The remain- ing two can be in a moment exposed. If with scissors a small window is made in the under surface of the abdomen of the cicada, it will be seen that the greater part of the abdomen is nothing but a large air cavity BUTTERFLIES, MOTHS AND CICADAS 213 and that all the essential organs are compressed into a narrow band above. This air cavity may be called the abdominal sac. We look forward into this vacant sac. In front we see a pair of stout white rectangular muscles that meet below in the middle line and diverge as they ascend to be finally attached to the posterior margin of the drum. These are the five organs to which I wish to direct attention : (i) the opercula, (2) the drum, (3) the shields, (4) the air-sacs, and (5) the muscles. In order to understand the mechanism of these different organs it Is necessary to examine the cicada while in the act of emitting its sound. I find the insect at sunset singing on the trees. When captured, it immediately ceases, but I squeeze its thorax and it again gives forth its note. With a pair of sharp scissors I snip off the opercula ; the sound continues ; the oper- cula therefore are not essential to the production of the noise. I amputate the shields. The music still continues ; so we reach a similar conclusion here. I decapitate the insect. Even then the sound may re- appear ; the mechanism is therefore reflex ; it is not in necessary subjection to the brain. I seek another specimen. It is playing loudly on a tree. Its abdomen is seen to distend and collapse in accordance with the increase and diminution of the pitch. While the note is low the body is more flaccid, but with a rising pitch the abdomen swells into a tense transparent globe. It would seem as though the abdominal sac was there- fore an essential organ for the production of the sound. Let us see. I catch the insect and make a little window into its abdomen so as to open freely into the sac. There can be no air pressure now, The air will 214 A NATURALIST IN HIMALAYA escape through the artificial hole. Yet the sound con- tinues. The air pressure within the sac is therefore not the essential cause. The only organs now left for investigation are the muscle and the drum. It is simple to experiment on these. I remove both drums and the insect remains permanently silent. I divide both muscles ; the result is the same. The cicada cannot utter another note. I take the divided muscle in a forceps and gently pull it and vibrate it. Even these clumsy efforts may generate a faint note. The conclusion is clear. The muscles throw the drums into vibration, and the vibrating drums originate the note. The matter must be considered a little further. A simple membrane thrown into vibration by a muscle could not produce this powerful sound unless there was something particular about its structure. Let us consider it in a little detail. The drum is a somewhat pear-shaped membrane about five-sixteenths of an inch in its lono-est and three-sixteenths of an inch in its shortest diameters. It has a pearly white appearance and is crossed by a series of brown parallel bands. Its mechanism is, I think, more easily understood if the drum is considered as consisting of two parts. First, there is the part of the drum which bears the ridges. It comprises the anterior half of the organ. The membrane is here soft and delicate. It is crossed transversely by five chitinous bars. The first of these bars is undeveloped and imperfect ; the second is more complete ; the remaining three are firm and strong and each is thickened in the centre so as to form a 5tout oval knob. Such is the ridged area of the drum, I BUTTERFLIES, MOTHS AND CICADAS 215 The second part Is the area which bears the tooth. It comprises the posterior half of the organ. It is composed of a hard elongated plate prolonged above into a distinct tooth that fits into a recess immediately beneath the knob on the last bar. The diagram (Fig. 8) ought to make clear the relationship of these two essential parts, the thickened ridges and the tooth. Now for the attachment of the muscle. When this is traced to its termination it is seen to end in a smooth Area bearing ndges Area bearing toofh Bar with central Knob Plate vvith centra i tooth Fig. 8.— Drum of Cicada. plate. A flat tendon then connects this plate to the posterior margin of that portion of the drum which bears the pointed tooth (Fig. 9). The muscle there- fore acts upon the drum and at each contraction pulls upon the tooth. A rapid succession of muscular con- tractions thus throws the tooth into a quick vibration. At each movement the tooth strikes against the thickened bar and a single sound is thus produced. Backwards and forwards moves the tooth. The bar is thrown Into a quick vibration and this originates the noise. There are left the other parts, the abdominal cavity, the operculum, the shield, 216 A NATURALIST IN HIMALAYA The function of the abdominal sac is to control the volume of the note. The cavity is in direct communi- cation with the inner surface of each drum. When the tension of the enclosed air increases then an additional pressure is thrown upon the membrane ; the bars are more tightly stretched, and therefore, as in the case of a violin string, they give rise to a more powerful note. The function of the opercula is obscure. They lie so close upon the abdomen that they force the sound ■{Oorsal surface of i^.^aDaominal I segment. Drurn. Chitlnous rod of drum. Tooth of drum. Tendon connectfn^ muscle fo tooth Plate at end of muscle. Muscle Ventral surface of i^^'abdomfnaJ segment Fig. 9. — Diagram to show essential parts of musical organ of Cicada. to issue through a narrow slit, and this probably increases the intensity of the note. It may also be possible that the opercula serve to direct the sound in a special direction suitable to the purpose of the insect. Nevertheless, these suggestions do not seem to me sufficient to explain the function of such large and conspicuous organs as the opercula. The shields are merely what their name implies : they simply protect the fragile drums. vSuch is the musical organ of the cicada, a perfect BUTTERFLIES, MOTHS AND CICADAS 217 mechanism of delicacy and power. It has no parallel in the insect world ; its sound has no equal but that of a steam whistle. Its component parts are those of a musical instrument. The pale membrane is the supporting structure ; the bars are the vibrating strings ; the muscle is the motive power and the tooth is the pointed finger that sounds the long refrain. The whole mechanism is a wonderful example of beauty, simplicity, and strength. It is the most perfect and exquisite contrivance of its kind that I have ever been privileged to see. CHAPTER XII GLOW-WORMS, TERMITES AND SHELLS Habits and luminosity of glow-worms— Their contests with snails — Flight and destruction of termites— Instincts associated with their distri- bution and preservation — Shedding of wings — Habits of ant-lions — Notes on the dispersal of shells. An insect common in the hills is the glow-worm, Lampyris. They usually frequent the low-lying- marshy portions of the valley, but I have found them glowing actively in the cold nights at an altitude of 8000 feet. The female, as is well known, looks like a large con- spicuous larva, while the male is small, active and winged. The glow-worms here reached a length of two and a half inches and shone with a very brilliant light. The banks of the irrigation channels, the edges of the rice fields, or the moist ground beneath a garden hedge were the spots where they were most likely to be found. The Lampyris lies quiet by day, motionless and showing no light. In the evening it grows rest- less ; its lamp begins to burn and it crawls off in search of prey. In addition to its legs, its power of propulsion is greatly aided by the last abdominal segment. This is sometimes used as a lever to push forward the body. It may also act as a hook to support the glow-worm when climbing. From the extremity of this segment the La7npyris can protrude a tuft of slender filaments each terminating in a delicate sucker. These suckers are a further aid to 218 GLOW-WORMS, TERMITES, SHELLS 210 progression, since by means of them the glow-worm can obtain a very firm hold. The insects also use these suckers for the purpose of cleaning their bodies. They feed on snails, and the mucus of the prey often smothers their bodies in slime. The glow-worms remove this by flexing their bodies and turning for- ward the tip of the abdomen so as to be able to brush away the mucus with their tuft of suckers. The large females shine with a very brilliant light. On the under surface of the eighth abdominal segment are two smooth white patches, oval in shape, one on either side of the segment. At night these patches emit a beautiful green light, of a penetrating nature, and resembling in colour the brilliant phosphorescence of the ocean. The light is fixed and steady ; it does not pulsate in the same rhythmical manner as in the firefly. The glow-worm shows a continuous gleam : the firefly is a twinkling star. Owing to the luminous patches being directed downwards, the lights are largely hidden from above. The portion of the ground on which the rays fall is a transverse patch, since the light spreads out on either side of the abdomen. One large female illuminated an area of newspaper one inch in length with sufficient intensity to enable me to read the print. None of the rays extend to the head of the insect, so that the light can be of no assistance in the findinor of food. Nor can it be thoui^ht that a light, so concealed beneath the abdomen that most of its rays are hidden, could be of much use for one insect to attract another. I do not think a glow-worm is capable even of perceiving a light. At all events, one, which I kept apart for twenty-four hours, did not seem to take any notice of a brilliantly glowing female 220 A NATURALIST IN HIMALAYA which I held close to it. Indeed, they seem to be almost destitute of any special sense. I have seen them pass and repass within half an inch of their prey quite oblivious of its presence, and then, after running accidentally against it, commence their fierce attack. Glow-worms are active throughout the whole night, not continuously, but at intervals. An hour before dawn I have seen them shining in the damp fields, and some, which I kept in a box, were brilliantly phos- phorescent when the first rays of light were appearing in the sky. The glow-worm is provident of its light. By day it is usually extinguished ; at night its intensity seems to depend on different causes. It is not the dark that stimulates luminosity, for I watched glow-worms kept in a dark box throughout the day and they showed not the trace of a glow. There seems to be a relation between general bodily activity and luminosity. An energetic glow-worm is usually the most brilliant. By day the insects are motionless, but I once saw one of a group distinctly active in the daylight and it showed a clear glow. Mechanical stimulation induces luminosity. If a glow-worm is stroked on the dorsal surface it often displays its light. I severed one trans- versely a short distance behind the head and the phosphorescence continued for two minutes after de- capitation, but the muscular contractions of the limbs and abdomen still remained and were quite active one and a quarter hours later. The light of the glow-worm does not burst suddenly into full flare as in the case of the firefly. It appears gradually and comes slowly to a maximum. Its disappearance is even more gradual, fading imperceptibly away. Fireflies are GLOW-WORMS, TERMITES, SHELLS 221 replete with energy ; glow-worms stolid but inert ; so it is with their luminary organs ; the one pulsates with active flashes, the other burns with a steady glow. The two luminous areas usually shine together, each with the same intensity. This, however, is not essential. I once watched a orlow-worm in which the patch on the right side was glowing, while that on the left showed not a trace of lii>ht. A faint pleam soon began to appear in the non-luminous area which, gradually increasing, at length equalled the brilliancy of the right. Thus it would seem that the nervous stimulus which controls the light may have either a unilateral or bilateral action. Moisture has a powerful influence in exciting luminosity. Glow-worms are most activ^e and usually congregate in damp places. After a shower of rain or when a heavy dew covers the ground their phos- phorescence is more intense. I kept some glow-worms away from moisture for twenty-four hours. I then touched the luminous areas with a drop of water on a fine brush and the luminosity increased. Even by day, when the insects are inactive, the lights will often shine under the stimulus of a drop of water, and within a minute of comins: in contact with the moisture, they often glow with the same brilliancy as at night. If the insect is then placed on a piece of blotting-paper to remove the moisture, the luminosity will disappear. Of seven glow-worms that I kept in a tin box, I noticed that only two were feebly shining on a clear dry evening. I allowed some water to drop gently amongst them so as to resemble the falling of rain, and as each glow-worm felt a drop of the fluid, it immediately became more active, began to 222 A NATURALIST IN HIMALAYA show its light, until in a short time all were glowing brightly and creeping in every direction over the floor of the box. Also when I placed a box of glow-worms in a shower of rain many of them became phosphor- escent even before sundown. It is not essential to moisten the luminary organs, for a drop of moisture on the head of the insect produces a similar effect. The fluid has therefore a retlex action. The moisture increases the muscular activity of the glow-worm, so that it might be thought to excite luminosity in the same way as gently stroking the insect's back. But this is not so. Irritating the glow-worm by blowing at it or stroking it never produces the same intensity of glow as does the presence of a drop of moisture. Contact with moisture has a special power in develop- ing the luminosity of these insects. It is not alone water that excites the light. A drop of spirit has a similar effect, and none shine more vividly than those which are enveloped in the moist and viscid mucus thrust over them by snails. Moisture of any kind is the chief stimulus to luminous activity. At night it is not the influence of darkness that calls forth the light, but rather the profuse dew that covers all the ground. The insects which I kept in absolute darkness by day showed no light. Nor is it the case that the advent of darkness coincides with the appear- ance of the glow-worm's light. Luminosity does not appear until an hour or more after sundown, when the earth has sufficiently cooled to permit the deposit of a layer of dew. In all likelihood the luminous activity of the glow-worm is under a rhythmical sway, appearing by night and disappearing by day through the regular pulsations of an internal nervous mechanism. But GLOW-WORMS, TERMITES, SHELLS 223 this mechanism is dependent in part on external stimuH of which one of the chief is moisture and one of the least important is the absence of light. Phosphorescent animals in general live in close association with moisture. The luminous inhabitants of the sea exemplify this. Not only many of the species that live at great depths, but the little globular Noctihica that stain the surface of the ocean with patches of rusty red, are brilliantly phosphorescent. The glow of the Noctihica resembles that of the Lainpyris, the light being a similar shade of green. It is specially attractive on a summer night in the Persian Gulf. The surface of the ocean gleams with light. Each little ripple is an evanescent glowing gem, one amongst millions in the quivering sea. From the bows of a ship two curling" waves diverge, displaying first their gleaming crests, and then, spread- ing into a sheet of foam, they shine like burnished silver. Porpoises roll in rivers of light, and flying-fish, in glistening streaks, flash through the dark sky. The phosphorescence of animals is as beautiful as its origin and object is unknown. Glow-worms have long been known to feed on snails. I witnessed the attack of a large glow-worm on its prey. The snail was crawling over the ground, and the Lavipy^^is, coming up behind it, climbed on to the shell and remained seated on the summit while the snail moved onwards. The elow-worm then gradually altered its seat on the snail's back ; it methodically worked itself into a position suitable for attack until its head projected forward over the anterior edge of the shell. The beetle was now firmly fixed. By means of its hind suckers it had a 224 A NATURALIST IN HIMALAYA secure hold on the shell, and its head overhuno- the soft body of the snail in readiness to strike. Suddenly, and with much greater rapidity than might be expected from so sluggish an insect, the Lauipyris plunged its head beneath the front margin of the shell. Immedi- ately the snail withdrew its head into the shelter, but the retreat was too late. The glow-worm's mandibles were already fixed. The snail struggled. Large drops of viscid mucus oozed out from beneath its shell, but this did not affect the glow-worm. The snail squirmed from side to side, now rolled its body to the right, now to the left in the struggle to throw off its enemy. Its efforts were of no avail. Deeper and deeper sunk the head of the Lampyris into the soft tissues of its prey. The victim was doomed. There was no escape from such an attack as this. The snail writhed in agony ; every muscle was convulsed ; the whole body swayed in violent contortions ; the thick fleshy foot was twisted into a rigid corkscrew, then untwisted, then again rescrewed, then curled up in the vain effort to sweep its enemy off the shell. Every gland poured out its mucus until enemy and victim were both en- veloped in the same slime. But the glow-worm still clung on, persisting in its fierce attack. Its mandibles were now deeply buried. It seemed to be striking at the very vitals of its prey. Its luminous powers shared its muscular efforts, for it glowed with an intense light. Its hold on the shell was firm. Its suckers had a secure grip. No bodily contortion could unseat it. And its place on the very summit of the shell was so well chosen that, no matter how the snail twisted itself to the right or to the left, it could never crush its adversary between its shell and the ground. GLOW-WORMS, TERMITES, SHELLS 225 After aljout ten minutes the snail had clearly given up the struggle. Its efforts slowly died away. In eight minutes more it was quiescent, and the glow- worm withdrew its head, now covered in a dense mass of snail-flesh and slime. It then commenced to clean away the mucus from its head and limbs, and this being complete, it again returned to its victim. Slowly it mounted to its previous seat on the shell, and bury- ing its head in the under surface of the snail's foot, it began to devour the dying flesh. The brilliant light now subsided to its normal glow, as though to mark the end of this little tragedy of nature. Hour after hour the Lampyris clung to its vanquished prey, and not till fourteen hours had elapsed did it cease to feed on the flesh which by then was decomposed and putrid. Who would think that these pretty glow-worms would join in so intense a battle ? The face of Nature may deceive us, we see so much apparent peace. The birds, the butterflies, the fishes of the sea, all the brilliant tints and joyous notes seem to bear witness to a life of happiness and concord. Yet how false is such a picture. All is war and carnage ; greed and cruelty are the ruthless weapons with which Nature fights, and every living creature must be a victor or a victim in the battle. Would that we could believe that the little glow-worms, apparently so innocent and gentle, were beautiful merely to be beautiful, and glittered with a bright green starlight merely to illu- minate the world around. But they play a sterner part. They occupy a rough place in life's struggle. They wage a cruel and relentless war. I pass now to another of these contests in which life 226 A NATURALIST IN HIMALAYA is pitied against life. The termites, or white ants, were not very common at the altitude of this valley, but they were sufficient to indicate how great is the destruction of certain species at some special moment of their lives. At the time of the emergence of the sexual forms of the termites another drama is opened to our view. A seething mass of insect life swarms about the aperture of the nest. The workers have broken through the galleries ; they have excavated apertures in the sides of their tunnels throuoh which the winoed forms can easily emerge. Out they come in a dense throng. They squeeze themselves through the newly opened doors ; others follow in thousands ; a few push their way back into the tunnels, but the main body, after crawling for a few minutes about the opening, scramble up the stems of the bushes or the blades of grass and then take wing into the air. The soldiers and the ordinary workers remain busy about the apertures. They are filled with activity and energy. They seem to realize the importance of the event. The soldiers resent the slightest intrusion or interference. They are ferocious to a degree. If touched, they make an immediate attack. They drive their sharp curved fangs into the skin and exude a milky irritating juice. Let us follow the winged forms into the air. Their journey is a short one. The sharp eye of an insec- tivorous bird soon detects them and they are instantly devoured. Other termites rapidly follow, but their enemies have found them out. Birds great and small come flocking to the scene ; little chats and bulbuls vie with hawks and pariah kites in the work of GLOW-WORMS, TERMITES, SHELLS 227 carnage. All nature appears set on their destruction. Round about the nest the crows and mynas con- gregate in hundreds, devouring the living morsels as they emerge into the light. Those that succeed in escaping into the air are seized by drongos, shrikes or bulbuls that dart out from every tree. Swifts and swallows meet them at higher altitudes, and kestrels swoop down on them from above. I sat down beside a nest and watched the ants emerge to take wing upon their fatal voyage. Thou- sands of hungry birds were cackling and chattering in an angry tumult or were darting and swooping through the air. I carefully noted the fate of fifty consecutive termites as they embarked into the sky, but not one of them succeeded in travelling thirty feet before it was devoured. On all sides could be heard the incessant snapping of beaks and the rustling of feathers. I could not see a single insect escape. Not only were the insectivorous birds devouring them, but the house-crows and jungle- crows were snapping them on the wing, pariah kites, both with feet and beak, were seizing them in the air, and at one moment no less than six kestrels were hovering over them or swooping on them from above. A filthy scavenger-vulture was swallowing them greedily from off the ground, and those which I protected at the mouth of the nest were being attacked by a host of carnivorous ants, to be dragged again beneath the soil. Nor is the emergence of the termites a mere event of the passing hour. Its memory still lasts, for two days later the jungle- crows were still congregated around the nest as though in anticipation of a further feast. 228 A NATURALIST IN HIMALAYA I know of no other living creature that has such an array of enemies or that loses such thousands that one may live. At this one nest I counted sixteen different species of birds all joining in the common feast. On the shrubs around were sparrows, shrikes, buntings, mynas, drongos, bush-chats and three species of bulbuls. Higher in the sky were swallows and swifts, and the larger birds were represented by house-crows, jungle-crows, kites, kestrels and vultures. I would never have thought that buntings would have forsaken the seeds of the fields or scavenger-vultures their foul refuse to feed on insects, and on another occasion I have seen both owls and seagulls captur- ing them in the air. When the termites emerge all flock to the feast ; the old accustomed food is forgotten ; all aid in the work of destruction. I do not believe that in the broad daylight a single inhabitant of this nest would ever have escaped its enemies. It was the darkness of night that saved them. They then face bats, reptiles and other insectivorous foes, but the shrieking multitude of the day, gorged to repletion, has slunk away to roost. The termites have now a chance of life. In the fading light of the evening I saw numbers of them hovering over the grass in my garden after their enemies had retired for the night. They had escaped in safety from the nest, were descending to the earth after their precarious flight, and alighting, were casting off their now useless winsfs. There are a few points worth notice in this sexual flight of the termites. It is interesting to observe in connection with the preservation of the species that the flight from the nest usually occurs a few hours GLOW-WORMS, TERMITES, SHELLS 229 before sunset. In this valley the termites were not numerous. I saw only four flights in the one season, yet all these flights took place an hour or two before dark. I have never seen a flight at any other time. So long as the daylight lasts the termites undergo a merciless destruction ; but as the darkness increases, many of them escape to found new colonies elsewhere. If the complete flight of all termites was to take place in the full daylight, the species would, I believe, in a few years become extinct. Another fact which must be of some importance to the survival of the swarm is that the termites in their nuptial flight ascend to comparatively great heights. They soon pass beyond human vision ; but, from the way the swifts and kites can be seen hawking after them in the air, it is clear that many must reach an altitude of at least a thousand feet. This instinct which impels the termites to considerable elevations must be a distinct aid to the survival of the species. In the first place, the insects are liable to meet with high aerial currents which will waft them over long distances and in this way increase their area of distribution. But a Qrreater advantag-e must rest in the fact that those individuals which reach a con- siderable height will leave behind them a host of enemies, and will therefore be the more likely to survive. No doubt they meet swallows, swifts, kestrels, kites, at all elevations, but they have escaped the far greater multitude of insectivorous creatures that would decimate them near the ground. Towards the termination of the flight the termites seem to undergo a natural exhaustion. They descend vertically from the higher elevations as though they 230 A NATURALIST IN HIMALAYA had no longer sufficient strength to propel them further through the air. They fall upon the grass and bushes, then climb out upon the twigs, the leaves, the stones, where they begin forcibly to vibrate their wings. Another point to be noted in the nuptial flight is the fact that the termites seem to possess a definite sense of direction. Indeed, from the way they are often seen to move all in the same course, it might almost be said that their flight was in a sense a migration of the swarm. The insects, when they first escape from the nest, seem somewhat confused. They are lost amidst the entanglement of trees and jungle and they flutter aimlessly about. But their instinct is to ascend. Soon they clear the trees, and then it is obvious that all the termites are pursuing the same predestined course. They are free from obstruction in the clear air, and then all move in the same direction and in one uniform flow. It is difficult not to believe that all are guided by some special sense to move in a common line. It has often struck me as a remarkable fact that many colonies of termites scattered over a wide area will often give forth their sexual forms all at the same time. I recall the first flic^ht of the season. Many nests, perhaps thirty or forty in number, dis- tributed over an area of about five square miles and through a zone of altitude of 600 feet, were all in eruption at the very selfsame hour. There was no connection between these nests, yet all burst into activity as though it was a single swarm. What force is it that can so influence these termites as to cause a number of widely separated nests to send forth their sexual forms at the same moment of the same day ? GLOW-WORMS, TERMITES, SHELLS 231 There seemed to be nothing- pecuHar in the conditions of the atmosphere. Clouds hung about the hills, and there was a sensation of impending rain. But this is scarcely sufficient to account for such a uniform effect. Whatever may be the original cause of the phe- nomenon, I think there can be little doubt that it is of real value to the propagation of the species. No one has shown with greater force than Darwin how danorerous are the effects of close interbreedino; and how marked is the improvement in both vigour and fertility that follows on the union of different strains. This, 1 think, must be the object that Nature has in view. It secures the special benefits of fertiliza- tion that follow on the union between different nests. For this reason all emerge at the same time and interminMe in one common stream. We can seldom understand how Nature works ; we can only wonder at the results that she attains. The shedding of the wings is an extraordinary phenomenon. It takes place so suddenly, all four wings at the same moment, that it looks as if it were a premeditated and voluntary act on the part of the insect. I do not think that this is the case, for if the insect is decapitated and the brain thus removed, the wings will still fall off. Nor is the flifrht throuo^h the air or the vigorous vibration and flapping of the wings which the insect makes after alighting in any way necessary, for I find that, if an insect is captured before flight and confined beneath a watch-glass where it can scarcely move, the wings will still come away. The act is hastened by any sudden stimulus. Decapita- tion, puncturing the thorax, even mere handling of the insect, may cause the wings to be cast off. 232 A NATURALIST IN HIMALAYA After the winces have fallen the insects then hide themselves beneath the stones or make their way into the crevices in the ground. They commence to dig but make only slow progress. By the following morning many are still so near the surface that they are unearthed by the hungry crows. I do not know at what moment sexual union actually occurs. Any one who has watched a flight of termites will have noticed how, after the wings have fallen, the insects do not wander indiscriminately about, but rather separate themselves into distinct pairs. The ground is often covered with these segregated couples, yet actual union is never seen. I am inclined to think that the object of the termites in separating into sexual pairs is not, as might at first be imagined, to secure immediate union. It is rather a device to make certain that each new nest which is established should contain a productive pair. The loss of life amongst the termites is so severe that certain special provisions must be made to help the survival of the race. This is one of these provisions : that whenever the time of union comes, the sexes may be found distributed through the ground in suitable sexual pairs. I pass to another neuropterous insect. Loose sandy patches, often on the summit of a low, rounded hill, might be found occupied by a colony of Myrme- leonid larvae. These ant-lions are well known, especi- ally the pits that they excavate in the sand to capture their prey. The hilly country was unsuited to their work, and I never saw them above 5000 feet. • The larvae are very small, not more than one-quarter of an inch in length. Each possesses a stout oval abdomen and a small head furnished with strong GLOW-WORMS, TERMITES, SHELLS 233 curved jaws. The larva lives at the bottom of a conical pit, and whenever there existed a smooth sandy area suitable for the construction of the pits, there a number of the larvae would congregate together in little communities of ten to twenty individuals, though each pit never contained more than one larva. The pits are from half to one inch in depth. A casual glance into the pit reveals nothing, but after careful observation with the eye close to the mouth of the pit, a pair of tiny jaws can be detected projecting like pin-points from the sand. The whole body of the larva is concealed ; only the tips of the open jaws appear in the pit. Small insects, especially ants, are continually falling into these pits. When crawling leisurely over the surface they usually appreciate their danger when on the brink of the precipice ; but if in the slightest degree alarmed, they stumble over the edge, fall into the trap, and are seized in a pair of powerful jaws. The ant struggles to escape ; it tries to scramble up the sloping side of the abyss while the ant-lion firmly clings to it below. It strives to drag itself from this grasp, but only tears down the soft crumbling sand which engulfs it still more firmly in the pit. Should it break away from the cruel jaws, the ant-lion throws up in the air little spouts of sand, and these in their fall sweep the victim back. At length it is drawn deeper into the snare by the traction of those powerful jaws, and is buried in the debris that it has pulled down upon its own head. Thus engulfed, escape is no longer possible ; the ant-lion at leisure devours the juices of the insect's body, casts the empty shell out of the pit and lies in wait for a fresh victim. 234 A NATURALIST IN HIMALAYA Ant-lions are cannibals. I took a larva from one pit and placed it in another pit. The owner resented the intrusion and treated the strano^er with the same severity that it metes out to any other insect. I observed on more than one occasion that, after an ant had succeeded in escaping from the pit, it moved about with the greatest circumspection, study- ing every step for fear it might fall into a similar trap. The ant had apparently benefited by its rough ex- perience ; its mind had proved susceptible to a simple education which is the most certain test of animal intelligence. The mode of construction of the pit is ingenious. The larva commences by crawling backwards and using the point of its abdomen as a shovel, by means of which it digs its way under the surface of the sand. After disappearing from view it moves round so as to make a circular furrow beneath the soil. This circle is the aperture of the pit. From within the circle it then commences to cast out the sand and thus deepen the depression. The sides slope gradually downwards to the bottom of the pit where the ant-lion lies buried. After the trap is fully con- structed, little particles of sand are continually falling down the crumbling sides, but are immediately thrown out by the occupant. As well as I could observe, the larva fixes its stout abdomen in the sand, and, using this as a point of fixation, it jerks the head and jaws suddenly upwards and pitches out at each thrust a little cloud of sand. The strength of the creature must be prodigious in proportion to its bulk. I have seen it hurling clear out of the bottom of the pit small pebbles ten to GLOW-WORMS, TERMITES, SHELLS 235 twenty times its own weight. It works very inter- mittently, a long pause being made after a few violent exertions. This must be a necessary division of rest and labour in a creature that employs such sudden and impetuous efforts. Should a stone, which is beyond the strength of the larva to remove, tumble into the pit, it burrows a little to one side until clear of the obstruction, then commences to hurl up sand, and thus constructs a fresh dwelling-place by shifting laterally the bottom of the pit. On a still day the ant-lion patiently waits in the floor of its funnel till the unwary ant tumbles in. But in windy weather the larva leads a more strenuous life. The force of the wind continually levels the surface of the sand ; every depression in the ground is to some degree lessened and the pit of the ant-lion tends to be filled in. Grains of sand pour down the sides of the pit ; it would soon be flush with the surface did not the ant-lion make every effort to contest the downpour. It hurls out the sand as fast as it rolls in ; in circles it revolves round and round the bottom of its cone, pitching out the sand that would engulf it. Every day of wind is for this larva a day of continuous toil. Though ant-lions are almost always seen waiting in the bottom of their pits, yet they sometimes wander about on the surface of the sand. A number seem to move about at the same time, leaving in their tracks lines of sinuous furrows as though a crowd of tiny snakes had been creeping through the dust. I will now mention a few observations on the fresh- water shells of the valley. The dispersal of shells is a subject which has excited the interest of our greatest 236 A NATURALIST IN HIMALAYA naturalists, and many interesting methods have been discovered by means of which the various species increase their geographical range. In this district man, by his mode of cultivation, seems to be the most important agent in effecting the dispersal of shells both of the land and the fresh water. On the broad fields in the beds of the valleys and on the narrow tiers of terraces rising up the slopes of the mountains the cultivator sows his crops of rice. Rice fields need an abundance of water ; in fact the crop, in order to thrive, must stand in a watery swamp. To effect this the cultivator diverts the water from the mountain streams and carries it in channels over the land. From the main channel smaller water- courses conduct the fluid to the cultivated area, and still smaller channels connect field with field. Thus vast expanses of land are fed with the water from one stream, and, by means of channels, all the fields of that large area are in intercommunication one with the other. Each field is swarming with molluscs, chiefly Liinncca, Pla7iorbis and bivalves, and, as the water flows from field to field, many of the smaller shells must be swept along with it. The molluscs also crawl on to twigs or adhere to the under surface of floating leaves, and are thus drifted along the channels from field to field. I think numbers must be floated away on leaves, for I collected many from a clump of herbage that had temporarily obstructed one of the channels. No living agent is so powerful as man in influencing the course of organic nature. Here the husbandmen sow large areas of their land with rice, and to nourish it they conduct the water from the streams, lead it by GLOW-WORMS, TERMITES, SHELLS 237 intricate channels into innumerable smaller water- courses. The land-shells that cover that area will be moved onward by the advancing flow, and the water- shells that occupy the mountain streams will be spread over the now swampy land. I will mention one other observation in connection with the dispersal of shells. Just below the summit of one of the forest-clad hills that confine the valley, and at an altitude of 8800 feet, I found a shallow muddy pool not more than twenty yards in width. A few other similar pools lay close by. The litde patches of stagnant water were completely isolated on this mountain top which was bounded by deep valleys on either side. Now this pool was teeming with bivalve molluscs. I never saw so many bivalves together in any pool. But I could not find a single univalve. The questions arise : How came this mountain pool to be stocked with shells, and why are there no univalves ? I see no other way by which shells could have been carried to a pool at such a height except in the way suggested by Darwin, namely by clinging to the feet of water-birds and being thus transferred from pool to pool. It might be thought that water- birds would never visit a mountain summit, but I was told by the Rev. Mr. Lawrence, who had observed the birds on this hill for many years, that he had records of a teal and a green sandpiper alighting on these pools. How are we to explain the presence of bivalves alone ? Is it not possible that bivalves with their power of grasping objects between their shells would be more likely to cling firmly to the toes or feathers 238 A NATURALIST IN HIMALAYA of birds and therefore be carried more securely than univalves ? Birds have frequently been shot with cockles clincrinof to their bills. Bivalves have been found with their shells firmly closed on the legs or antennae of water-beetles, or grasping the limbs of water-scorpions or the larvae of dragon-flies and other inhabitants of fresh-water pools. There would seem to be little doubt that the habit which bivalves possess of lying with their shells apart and closing tightly on objects introduced between them would make them more liable to transportation than univalves, and give them a greater opportunity of being the first arrivals at a newly formed and distant pool. This appeared to me the probable explanation of why this isolated pool should have been stocked only with bivalves. All creatures are dependent one on the other in the well-balanced scheme of life. One species is essential to another for food, to another for shelter, to another for the rearing of its young. Destroy any one species, and some other will surely suffer Even the life of the molluscs is interwoven with that of the higher animals in that they use the migration of the birds and the agricultural devices of man as an unconscious mode of transport to scatter them over the surface of the earth. CHAPTER XIII OBSERVATIONS ON MAMMALS Comparative scarcity of mammals — Observations on ilying squirrel — Habits and instincts of Himalayan monkeys — Emotional expression in the leopard — Contentment — Fear — Anger — Distress — Eagerness — Attention — Affection. The mammals that frequent this valley attract but little attention, and I have few remarks to make upon them. In the forest their scarcity is remarkable. For days we may wander over the pine-clad hills yet only on rare occasions are any mammals seen. A troop of monkeys in the trees, a fox or a civet sneaking through the jungle, a marten disappearing behind a rock or a flying squirrel at dusk gliding from tree to tree, are amongst the few species we may hope to meet. At intervals the report is spread of a bear or leopard in the woods, but these larger mammals are seldom seen. It is not in the thickest jungles but in the barren valleys of the Western Himalaya that we find the largest animals. The markhor and the ibex frequent the main Himalayan axis or the bieak ranges of the Karakoram and the HinduTCush ; the great sheep of Marco Polo is confined to the treeless plateau of the Pamir. So it is when we look more widely over the globe. I have never seen the larger mammals collected in such multitudes as on the grassy lands of East Africa. At one time I saw hartbec st, wildc- 239 240 A NATURALIST IN HIMALAYA beest, zebras, gazelles, ostriches, antelopes and giraffes all spread over an almost treeless plain. The whole landscape was literally covered with herds of these macrnificent creatures. Yet here, in all this luxuriance of Himalayan vegetation, we see scarcely a single mammal. How true is the remark of Darwin that " among the mammalia there exists no close relation between the bulk of the species and the quantity of the vegetation in the countries which they inhabit." I will mention a few observations on some of the more common species. For many months I kept in my possession a Himalayan flying squirrel, Petatt- rista inornatits, and never have I seen a tamer or a more engaging pet. It showed not the slightest fear of man, but took an unbounded pleasure in scrambling over his body and playing with his hands and face. It looked on man as a playmate rather than as a foe. The contrast between the tameness and wildness of undomesticated animals when brought into a state of captivity is a very curious subject and one difficult of explanation. The cele- brated Sir J. Sebright states that the wild rabbit and the wild duck are the most untameable creatures he knows. So powerful is their instinctive sense of wildness that, even when taken from the nest, they defy all attempts to make them gentle and familiar. How different is the flying squirrel which, when captured in the adult state, soon becomes intimate and tame. Few creatures are more persecuted by man than the wild duck and the wild rabbit, few so seldom as these flying squirrels. I suspect that, in the case of the duck and rabbit, persecution by man has generated a sense of wildness from the fear of man, The Flying-Squirrel [Petaurista inornata). [Face p. 241.] OBSERVATIONS ON MAMMALS 241 and that this sense has become so fixed an instinct as to be transmitted to the offspring and to have de- veloped in them the same instinctive fear though they themselves have endured no persecution. If any man could persist in the domestication of duc'.s or rabbits commencing from the wild stock, I have no doubt that he would eventually rear offspring as tame as the rabbits of the rabbit-hutch or the ducks of the poultry- yard. The tail of the flying squirrel is worth attention. It is long, thick and bushy. Its functions are two in number ; the one is its use as a warm covering to surround the head and body during sleep, the other is its employment as an agent to secure the animal's balance in the trees. I used to amuse myself by placing the squirrel on a smooth bar to see how the tail was exerted to maintain the creature's balance. The squirrel sits clutching the bar. Its claws cannot penetrate the surface, so that it must use all its powers of balance to keep its equilibrium. The tail hangs vertically down behind ; it is rigid, definitely held in that position for a special purpose. I draw the animal's head forward and up goes the tail to increase the counterpoise behind. I pull the hind quarters backward and the tail is swept forward beneath the bar and equilibrium is restored. I push the squirrel to the left and the tail is inclined to the right ; I push it to the right and the tail turns to the left. Any movement of the animal in one direction is met with a counterbalance of the tail in the opposite direction, and a uniform equilibrium is thus attained. This function of the tail is illustrated in another R 242 A NATURALIST IN HIMALAYA method. I place the organ out of action by fixing the tip of the tail to the back of the squirrel's neck. I again place it on the smooth bar. It makes vain attempts to keep its balance ; the tail struggles with its bonds in the endeavour to break free, and the squirrel may end by tumbling completely over, clinging with flexed claws to the under surface of the bar. Thus the main function of the tail is as an organ of equilibrium. It is a pliant wand gradually developed to its present length to enable its owner to keep its balance while it leaps and clambers through the trees. On occasions the flying squirrel completely inverts the normal position of its body and hangs back down- wards from the under surface of a branch. The tail, under such conditions, becomes curled round the branch from which the animal is suspended, and its position cannot but suggest to the mind that it actually is employed as an organ of support. Indeed it would only require a slight increase in the muscular tension in order to become so. Now in this striking attitude we may possibly detect one of the evolutionary gradations in the development of the prehensile tail, a trace of a gradual passage from an organ of equilibrium to an organ of prehension, from an organ which in the flying squirrel maintains a balance in the tree to one which, as in the American monkeys, actually grasps the branch in order to sustain the body. When the flying squirrel glides through the air its tail is held rigid and trailed out behind. It has been considered on these occasions to act as a kind of a rudder by which the animal can guide its move- ments and actually change direction when in the OBSERVATIONS ON MAMMALS 243 air. This can scarcely be the case. I have never seen the ghding motion take place in any direction but that of a straight line except in the sudden elevation at the termination of the "flight." Moreover, it is improbable that Nature would have provided the animal with a steering gear in the form of a cylindrical bushy tail. I think rather that it acts as an organ of balance, for of what value could the similar long bushy tail be to steer the common squirrel which never "flies".'* Just as the tail of a bird cannot act as a rudder because it is compressed in the wrong direction, so also it is unlikely that the tail of the flying squirrel will possess a steering function as it is not compressed at all. I have mentioned that, when the animal is seated on a bar, an excess of weight in the anterior portion of the body is counter- balanced by an elevation of the tail which increases the leverage of the posterior portion of the body. A somewhat similar mechanism takes place in the air. The squirrel when gliding is in an oblique position ; the anterior portion of its body is depressed. It will therefore tend to topple over forwards unless it has a sufficient counterpoise behind. To give it this counterpoise the tail is held rigid and trailed ; it acts as an organ of balance to maintain a steady flight. The mammal most commonly seen about the woods was the Bengal monkey, Simia rhesus. It is the same species that inhabits the plains, but at these altitudes it has developed into a more robust animal and has put on a thicker and warmer coat. This monkey is of a plain brown colour with a rusty tinge about the louer portion of its back. A red 244 A NATURALIST IN HIMALAYA face and a pair of red callosities behind are the only bright marks upon its body. It stands about two feet in height, and its tail is about half that length. It congregates in troops, thirty or more of both sexes and of all ages living together in the same pack. They haunt the forest, where they climb heavily amongst the trees, descend to the grassy glades, or pillage the cultivated tracts about the villages. They pass the day incessantly scratching and picking at one another, turning up the stones and leaves in search of seeds, joining in noisy squabbles, or exploring one another's fur in the quest of imaginary fleas. The adults are the more sedate ; they often stretch themselves in the sun while the little ones toss about the o^round or grambol amoncrst the conifers and oaks. They are quarrelsome and pugnacious, are everlast- ingly hissing, biting and cuffing at one another so that the whole family seems as though it had some interminable dispute. It is an insolent and intrusive creature. It plunders fields, enters human habitations and even presses down into the crowded bazars of Simla. It sets up a show of audacity towards an intruder ; it assumes a threatening attitude, it growls, shakes itself, pretends to spring ; but it is all a sham and a pretence, it makes off before a real danger. At night they roost upon the trees, but by day they seem to feel more secure upon the ground, and when alarmed they will often come leaping to earth as though they feared to be isolated amidst the foliage. It is an intelligent and crafty creature. It is the monkey that is commonly carried by showmen throughout India. It is also clever in its native haunts, and I knew of an instance where a whole troop of these The Bengal Monkey {Siniia rhesus). Emotional expression in the Leopard. (i) Contentment. [Face p. 245.] I OBSERVATIONS ON MAMMALS 245 monkeys used regularly to utilize a long pendant branch as though it were a rope to swing themselves across a wide canal. Their food seems to be ex- clusively of a vegetable nature. They are continually munching the young shoots, leaves, buds and flowers of the trees, pulling at the roots, turning up the stones for seeds, or robbing the grain from the husbandman's field. The sexes come together in September, but there is no disintegration of the herd ; in March the young are born, a single offspring at each birth. At first the young is carried in the mother's arms ; later it clings into her hairy coat, and either hangs suspended from her belly or rides astride upon her back. They have different notes and intonations in accordance with the emotions and excitements of the time. The usual cry is a plaintive wailing note. It is answered by the other members of the herd ; it is the note of alarm that spreads the news whenever danger is near. The sound of a quarrel is placed in a higher pitch. A shrill vibrating hiss is the voice of anger and fight, while a hoarse growl is the note of defiance towards an intruder. The largest males are powerful beasts. They are heavy and massive, with stout muscular arms, bright red faces and thick hairy coats. They often le£id and direct the movements of the herd. They permit of no interference. They exert authority, maintain discipline, intervene in quarrels, chastise offenders, settle family disputes. The herd is obedient to their rule, and strife for a time fades away beneath their sway. I observed a few interesting facts connected with their instincts. I once had a female of this species 246 A NATURALIST IN HIMALAYA which had no offspring of her own. One day she happened to find a pair of young kittens only a few days old. She immediately took this unnatural offspring under her charge ; she nursed them with the greatest care and would allow no one to take them from her. It illustrated how easily the maternal instinct becomes vitiated when it cannot fulfil its normal course. Another incident seemed to show how quickly an instinct acquired by the parents may become innate in the young. These monkeys dread the sight of a gun. They have learnt to know its power, and are terrified if they see a weapon pointed at them. But a very young monkey was on one occasion chained in my garden. It could never have seen a gun, and certainly could scarcely have learnt what the power of a firearm meant. Yet the very first time that I raised a gun towards this little animal it burst into the greatest frenzy and alarm and commenced to hiss and leap upon its chain. It showed little fear of a stick even thouoh threatened with a beating, yet if the stick was directed towards it in the attitude of a gun then all its passions were again aroused. Are we to conclude that this little creature was born with the dread of a gun as one of the innate instincts of its nature? It had no ex- perience of firearms in its own short life, and unless it was taught these dangers at a very tender age by some of the older members of the herd, it must have inherited from its parents that instinctive dread which they had learnt by experience throughout the preceding generations. When herds of these monkeys are observed from below feeding on a mountain side, it is not unusual to OBSERVATIONS ON MAMMALS 217 sec stones come hurtling down the cliff as though they were missiles thrown at the intruder. For a long time I doubted the statement of the hillmen that the monkeys actually did employ stones as weapons to drive away an enemy ; I thought that the stones must be simply dislodged by chance. But I have no doubt that the hillmen were correct. For at last I saw one of these monkeys deliberately tilt up a large stone and roll it towards me down the slope. This I take to be the most rudimentary manifestation of the more elaborate instinct that employs weapons as a mode of protection or offence. It is the first trace of that higher judgment possessed by other monkeys of selecting stones of suitable size and shape to use as weapons against their foes, or of the skill with which the female orangutan breaks off branches and spiny fruits from the trees to hurl them to the ground in a shower of missiles. The only other monkey that I observed in the dis- trict was the langur, Presbytis schistaceus. I saw very little of it. It keeps to higher altitudes than the Bengal monkey, usually remaining above 6000 feet, and I have seen it near the tree limit at 11,000 feet traversing the fields of snow. It is a handsome animal of a slate colour above, yellowish beneath, and carries a long, slightly tufted tail. Its black face is very conspicuous, since it is encircled in a white fringe. It stands two and a half feet in height, while its tail is about three feet in length. The langur seems more arboreal than the Simla. Large troops composed of both adults and young leap about the trees and make a great noise as they crash heavily through the forest. It feeds on grain, fruit, leaves 248 A NATURALIST IN HIMALAYA and buds. It loves die neclar of flowers, especially that of the rhododendron. Indeed, it is a strange contrast to see the black face of the langur with its white encirclino; fring-e holding: in its mouth a bunch of crimson rhododendron. It appears to be less quarrel- some than the Simia, though in winter, when the langur is driven down to lower altitudes, pitched battles are said to occur between the two species. The leopard, Felis pardus, was distinctly uncommon in the district. I once kept a cub of this species, which was captured on the hillside, and took some little trouble in noting- the chanores in its actions and expressions under the influence of different emotions. I will attempt to indicate these various changes, which may seem more evident with the help of the illustrations.^ (i) Contentment In the contented and restful state when, after a satisfying meal, the animal lies partly curled upon the ground and the body and mind are calm and quiet, or when the mental faculties are in complete abeyance during sleep, there is no rigidity of the trunk or limbs, no twitching of muscles or changes in facial expression ; the whole animal is limp and sup[)le, its voluntary musculature is in a condition of physiological rest in complete unison with the calm ^ My observations on the emotional expression of the leopard and my notes on the flying-squirrel have previously appeared in the Journal of the Bombay Natural History Society. My photographs of these two animals and also that of the Indian robin and the nest of the paradise fly-catcher have likewise been published in the same journal. I am indebted to the Honorary Secretary of th^t society for his kind permission to reproduce them here. I M y M ^ ,* EMOTIONAL EXPRESSION IN THE LEOPARD. 2 (upper) Fear, 3. (lower) Anger, [Face p. 24S.] OBSERVATIONS ON MAMMALS 249 and inactivity of its mind. Occasionally, while coiled in this contented state, the sight of some passing object may excite the interest of the animal. It raises its head, opens wide its eyes and looks steadfastly towards the object producing this mild excitement ; the lower jaw drops and the mouth opens but not in anger ; the whole countenance alters and the blank expressionless facies which characterized the animal in its state of pure contentment is changed instantane- ously to one of interested intelligence. (2) Fear Fear in a wild animal must be frequently associated with anger, and perhaps preceded occasionally by astonishment, though the latter would be difficult, if not impossible, to detect. It does seem possible, however, to obtain the expression of fear distinct from that of anger, if the object causing the fear is so powerful as to overawe the animal to such a degree as to prevent it from displaying its anger. A leopard, when enduring the emotion of fear pro- duced in this manner, acts in a very distinctive way. It lowers its body into a crouching postiire and throws its ears well back. These movements have an object. They tend to lessen the apparent bulk of the animal ; and as many of the lower creatures in such conditions of danger, as would create the sensation of fear in the higher ones, do diminish markedly the volume of their bodies and by such diminution obtain definite protection, it is probable that these movements are instinctive tendencies inherited throuohout a lonij ancestry, but which now display little, if any, service- able manifestation. 250 A NATURALIST IN IIII\IALAYA The head during fear is often turned in the opposite direction to that from which the danger is expected to arrive. The eyes are partially closed, and tighdy so if the fear amounts to terror. The nostrils are pinched so as to give the face a characteristic expression. These acts also have a purpose. It is a natural instinct in the higher animals to turn away the face if any special injury is directed towards it, and to close the eyes cither partially or completely and contract the nasal orifices in order to give protection to the delicate organs contained within, and in the leopard this instinct seems to be so highly developed and so easily called into action as to occur in general states of fear, even when the danger is not specially directed to the sensitive organs of sight and smell. The limbs and tail are held stiff and the body loses its great muscular laxity. The corners of the mouth are raised, the upper jaw elevated, the lower jaw depressed, the mouth is partially opened and the canine teeth dis- played. The general facial expression is one of fierceness, and when a wild carnivorous animal is in fear or terror it must undoubtedly be fierce. The domestic cat when terrified has been described as arching its back and erecting the hair over the whole body, especially on the tail, and as raising the basal portion of the tail upright and bending the ter- minal extremity to one side. I have never noticed this attitude in the leopard, nor by experiment have I been able to obtain anything resembling it ; and it is possible that, owing to the great strength of the animal, it would not, in its native haunts, experience fear to any great extent, and would therefore not have the emotion so highly developed and exhibited in a OBSERVATIONS ON MAMMALS 251 manner exactly similar to that seen in the weaker and domesticated creatures of its kind. (3) Anger, Rage Anger and rage, so frequently associated with fear, are expressed in a very similar manner. The body again crouches and, if the animal is savage, may be lowered completely to the ground. The trunk and limbs are rigid, the claws thrust out and the tail usually stiff, though it may be curled from side to side. These actions have a purpose ; they are the characteristics of an animal about to struggle for its prey. The crouch- ing and rigidity maintain every muscle tense and ready instantaneously for the spring. The claws are projected for the fatal blow. Possibly no cause excites the anger of a carnivorous animal so intensely and so frequently as the prospect of a coming battle, and consequently those characteristics, which are of direct service to an enraged animal about to fight, have become so engrained into its nature as to be instinctively associated with its anger under all conditions, even when there is no suggestion of a fight. The rigidity of the tail is due to the muscles of that organ acting in harmonious contraction with those of the rest of the body, and the occasional curling motion may be an involuntary liberation of that great excess of muscular energy which must be effervescing through its bodily system. The angles of the mouth are elevated, the nostrils drawn together, but the whole face appears less con- tracted and pinched than when the animal is expressing true fear. The canine teeth are displayed in an open mouth and, when the anger amounts to rage, the whole row of teeth becomes clearly seen. The face is directed 252 A NATURALIST IN HIMALAYA towards the object which excites the anger, and the animal hisses or emits a deep guttural snarl. These marked changes of facial expression and utterance of sound also serve their purpose ; they give to the animal a fierce and savage appearance, and are there- fore of service to it by causing it to strike terror into the mind of the creature against which its anger is directed. I have never seen the hair erected durin