1. Paramecium. (From "Animal Biology." Longmans). PAGK 4 2. Behaviour of Paramecia. (After Jennings, American Journal of Psychology). 8 3. Cell-division. (From "Animal Biology." Longmans) 13 4. Wapiti with antlers in velvet. (Drawing by Mr. Charles Whymper, after photograph by Miss Reynolds). 5. Wapiti with velvet shredding off. (Drawing by Mr. Charles Whymper, after photograph by Miss Reynolds) 6. Sun-dew leaf and tentacles. (From Darwin's "Insectivorous Plants." Murray. By kind permission of Mr. Francis Darwin, F.R.8.) 7. Venus's Fly-trap. (From Darwin's "Insectivorous Plants." Murray. By kind permission of Mr. Francis Darwin, F.R.S.) 8. Flower of Valisneria 27 28 30 9. Flower of Catasetum 10. Flower of Catasetum dissected. (From Darwin's "Fertiliza- 11. Solitary Wasp stinging Caterpillar. (After Plate III. in Dr. and Mrs. Peckham's "Solitary Wasps") 12. Solitary Wasp dragging a Caterpillar to its Nest. (After Plate IV. in Dr. Peckham's "Solitary Wasps"). 13. Insect Larvæ: Sitaris, Argyromoba, and Leucopsis. (After Fabre "Souvenirs") . 14. Yucca Flower and Moth FIG. 15. Newly-hatched Chick swimming. (Drawn by Mr. Charles Whymper, after instantaneous photographs and a sketch by the author). . 16. Nestling Megapode. (From Dr. R. Bowdler Sharpe's "Wonders of the Bird World." Wells Gardner) . . PAGE . 85 87 17. Cuckoo ejecting Meadow Pipit. (From Mrs. Hugh Blackburn's sketch in "Birds from Moidart." David Douglas). 91 18. Leaf-case of Birch-weevil . 19. Solitary Wasp using a stone as a tool. (After Plate V. in Dr. Peckham's "Solitary Wasps"). 121 . 127 20. Spiders placed by Solitary Wasps in crotches of branching stems. (After Plate X. in Dr. Peckham's "Solitary Wasps") 133 21. Fox-terrier lifting the latch of a gate. (Drawn by Mr. Charles Whymper, after a photograph by Miss Alice Worsley). . 145 22. Cage used by Dr. Thorndike. (After figure in "Animal Intelligence," Psychological Review, 1898) 148 23. Diagram illustrating Dr. Thorndike's Experiments. (Based on data given in his monograph on "Animal Intelligence") 150 24. Wood ant. (From Shipley's "Invertebrates." A. & C. Black) 207 25. Beetle soliciting food from Ant. (After Wasmann. Enlarged) 213 26. Honey-pot Ant. (Enlarged) 215 ANIMAL BEHAVIOUR CHAPTER I ORGANIC BEHAVIOUR I. BEHAVIOUR IN GENERAL WE commonly use the word "behaviour" with a wide range of meaning. We speak of the behaviour of troops in the field, of the prisoner at the bar, of a dandy in the ball-room. But the chemist and the physicist often speak of the behaviour of atoms and molecules, or that of a gas under changing conditions of temperature and pressure. The geologist tells us that a glacier behaves in many respects like a river, and discusses how the crust of the earth behaves under the stresses to which it is, subjected. Weather-wise people comment on the behaviour of the mercury in a barometer as a storm approaches. Instances of a similar usage need not be multiplied. Frequently employed with a moral significance, the word is at least occasionally used in a wider and more comprehensive sense. When Mary, the nurse, returns with the little Miss Smiths from Master Brown's birthday party, she is narrowly questioned as to their behaviour; but meanwhile their father, the professor, has been discoursing to his students on the behaviour of iron filings in the magnetic field; and his son Jack, of H.M.S. Blunderer, entertains his elder sisters with a graphic description of the behaviour of a first-class battle-ship in a heavy sea. The word will be employed in the following pages in a wide and comprehensive sense. We shall have to consider, not only the kind of animal behaviour which implies intelligence, sometimes of a high order; not only such behaviour as animal play and courtship, which suggests emotional attributes; but also forms of behaviour which, if not unconscious, seem to lack conscious guidance and control. We shall deal mainly with the behaviour of the animal as a whole, but also incidentally with that of its constituent particles, or cells; and we shall not hesitate to cite (in a parenthetic section) some episodes of plant life as examples of organic behaviour. Thus broadly used, the term in all cases indicates and draws attention to the reaction of that which we speak of as behaving, in response to certain surrounding conditions or circumstances which evoke the behaviour. The middy would not talk of the behaviour of his ship as sho lay at anchor in Portland harbour; the word is only applicable when there is action and reaction as the vessel ploughs through a heavy sea, or when she answers to the helm. Apart from gravitation the glacier and the river would not "behave in a similar manner." Only under the conditions comprised under the term "magnetic field" do iron filings exhibit certain peculiarities of behaviour. And so, also, in other cases. The behaviour of cells is evoked under given organic or external conditions; instinctive, intelligent, and emotional behaviour are called forth in response to those circumstances which exercise a constraining influence at the moment of action. It is therefore necessary, in a discussion of animal behaviour, that we should endeavour to realize, as far as possible, in every case, first, the nature of the animal under consideration; secondly, the conditions under which it is placed; thirdly, the manner in which the response is called forth by the circumstances, and fourthly, how far the behaviour adequately meets the essential conditions of the situation. II. BEHAVIOUR OF CELLS From what has already been said it may be inferred that our use of the term "behaviour" neither implies nor excludes the presence of consciousness. Few are prepared to contend that the iron filings in a magnetic field consciously group themselves in definite and symmetrical patterns, or that sand grains on a vibrating plate assemble along certain nodal lines because they are conscious of the effects of the bow by which the plate is set in sounding vibration. But where organic response falls under our observation, no matter how simple and direct that response may be, there is a natural tendency to suppose that the behaviour is conscious; and where the response is less simple and more indirect, this tendency is so strengthened as to give rise to a state of mind bordering on, or actually reaching, conviction. Nor is this surprising for, in the first place, organic responses, even the simplest, are less obviously and directly related to the interplay of surrounding circumstances; and, in the second place, they are more obviously in relation to some purpose in the sense that they directly or indirectly contribute to the maintenance of life or the furtherance of well-being. Now where behaviour is complex and subserves an end which we can note and name, there arises the supposition that it may well be of the same nature as our own complex and conscious behaviour. Take for example the behaviour of the Slipper-animalcule, Paramecium, one of the minute creatures known to zoologists as Protozoa. The whole animal is constituted by a single cell, somewhat less than one-hundredth of an inch in length, the form and behaviour of which may be readily studied under the microscope. Thousands may be obtained from water in which some hay has been allowed to rot. The surface of the Paramecium is covered with waving hair-like cilia, by which it is propelled through the water, while stiffer hairs may be shot out from the surface at any point where there is a local source of irritation, as indicated at the top of the accompanying figure. |