“At the time I was making observations on a young greylag goose … Martina had acquired a fixed habit: … when she was about a week old I decided to let her walk upstairs to my bedroom instead of carrying her up … In our house in Altenberg the bottom part of the staircase, viewed from the front door, stands out into the middle of the right‑hand side of the hall. It ascends by a right‑angled turn to the left, leading up to the gallery on the first floor. Opposite the front door is a very large window. As Martina, following obediently at my heels, walked into the hall, the unaccustomed situation suddenly filled her with terror and she strove, as frightened birds always do, towards the light. She ran from the door straight towards the window, passing me where I now stood on the bottom stair. At the window, she waited a few moments to calm down, then obedient once more, she came to me on the step and followed me up to my bedroom. This procedure was repeated in the same way the next evening, except that this time her detour to the window was a little shorter and she did not remain there so long. In the following days there were further developments: her pause at the window was discontinued and she no longer gave the impression of being frightened. The detour acquired more and more the character of a habit, and it was funny to see how she ran resolutely to the window and, having arrived there, turned without pausing and came to me on the step.”