Information-seeking is usually conceived of as gathering information to make better decisions by observing and sampling from the external world. But for humans and many other intelligent agents, much of that information, once gathered, is also stored to guide future decisions, necessitating mechanisms for seeking information in some form of inner space. Here we survey various types of evidence suggesting that strategies adapted for search in external spatial environments are also used to seek information internally from memory. These include foraging strategies such as area-restricted search, which adaptively balances exploitation of locally clustered resources with exploration for resources more widely dispersed. We also describe how internal search satisfies the predictions of external foraging theory via the Marginal Value Theorem and show how these predictions can be used to investigate individual differences in memory search such as those caused by aging and cognitive impairment. Finally, we consider evidence that the structure of inner space may be a result of the very processes we use to search it.

Tikirt to Tazenakht.

25 October 1883.— Departure from Tikirt at 9 o’clock in the morning. I enter immediately into a vast desert that stretches, flecked every now and then with small oases, between the three Oueds Idermi, Aït Tigdi Ouchchen and Tazenakht. The appearance is the same everywhere: hilly terrain, trying paths; no vegetation, no living beings besides gazelles. The ground is made up of rocks and stones, sandstone whose surface, which seems burnt to ashes, is black and shining as if tarred. This rock, the only kind I see between here and Tazenakht, is prevalent all over the south. In the plains, it is like a crust of small, black, brilliant stones, a sort of scale covering the earth; in mountain country, like here, it appears in two ways: sometimes as a series of staircases whose steps are blackened and cracked, a heap of gleaming stones piled up, and sometimes as long, smooth, even tables. These are the desolate solitudes through which I travel; they make me dream of deserts of black stone which, in another region, S. Paulinus found outside the High Atlas. At four-thirty, I arrive at the oasis of Irels; I will spend the night here.

My route today was not the safest; the brother of Chikh Mohammed from Tikirt escorted me to Tagenzalt with two of his men; he left me there, confiding me to two men from that qçar who brought me to Irels. We met nobody during the entire journey. No watercourses. Tagenzalt, where I stopped for half an hour, is an independent locality, self-governing, but recognizing the sovereignty of the Tikirt sheik; it includes about fifty houses, built of adobe and surrounded by an enclosure; nearby are large, beautiful fields; date palms are numerous, but one sees pomegranates, figs, and aspen as well, with cultivated lands in their shadow. The oasis is located at the bottom of a small valley whose western slope is here a steep wall in which a dozen cavern-mouths open. There is no stream, no water besides a spring. Tagenzalt is, again, enclosed within ramparts: this is a particularity I am seeing for the first time here and which it is important to comment on.

Tissint

Upon arriving in Tissint, a new region began for me: the sky, crops, people, dress—everything is different here from what I have seen before this day. Until now I was in mountainous country, with the climate and products of southern Europe. The inhabitants were the Chellaha, almost all dressed in white wool. That country had the Bani as its border. When we enter Tissint, after crossing the Bani, we set foot into a new world. Here, for the first time, the eye is drawn toward the south but sees not a single mountain: the region to the south of the Bani is an immense plain, sometimes white, sometimes brown, its rocky solitudes stretching out as far as the eye can see; a line of azure borders it at the horizon and separates it from the sky: this embankment is the left bank of the Drâa, beyond which begins the Hamada. This scorched plain has no vegetation besides some stunted gum-trees, no other relief than narrow ranges of hills, rocky, interspersed, and twisted around like sections of serpents. Alongside the cheerless desert are the oases, with their wonderful vegetation, forests of palm trees always green, qçars replete with wellbeing and wealth. Working in the gardens, stretched out nonchalantly in the shadow of the walls, squatting by the doorways of houses and smoking, one perceives a numerous population of men with black faces, Haratîn of a very dark color. Their clothes strike me first of all: all are dressed in indigo cotton, a fabric from the Sudan. I am in a new climate: there is no winter here; they sow in December, reap in March; the air is never cold; above my head, a sky ever blue,

Tissint is one of the largest oases of the Moroccan Sahara. It is located at the bottom of a basin whose edges are the Bani on one side and a ring of hills—rocky to the south, sandy to the east and west—on the other. In the middle of this circle stretches a plain of white sand: there stands the oasis, a forest of palm trees crossed by a lovely river, with qçars rising up to the edge of the groves.

Tangiers to Tetuan

I disembarked in Tangiers on the 20th of June 1883, accompanied by Rabbi Mardochée. Having nothing new to see in this city, known through its many descriptions, I was eager to leave. My first stop was to be Tétouan, and I sought information immediately on the best means of getting there. It was a day's walk away; small caravans left daily from Tangiers; the road was safe; I would not need an escort. I fixed my departure for the following day.

Despite the short time I spent in Tangiers, the minister of France, M. Ordéga—to whom M. Tirman, governor general of Algeria, had kindly recommended me—prepared letters of introduction to his agents for me, with an unparalleled goodwill and graciousness; he gave me one from Moulay Abd es Selam, the renowned sherif of Ouezzane, commanding whomever was his friend to lend me help and protection; in short, furnished me with all the recommendations that I could need in the course of my journey. There was not a one that did not serve me well in the months that followed; thus I thought back, more than once, with gratitude on the generosity of which I had been the object.

21 June 1883

I leave Tangiers at three o’clock in the afternoon. My caravan consists of six or seven men, most of them Israelites, and ten or so beasts of burden. We first cross a series of small, wellcultivated valleys, separate from each other by borders of dwarf palms. Toward evening, we enter the valley of the Oued Merah; this is where we walk for the rest of the day, amid superb fields of wheat that cover the valley entirely. We stop at nine-fifteen near some hutlike shelters, and spend the night in this place. The road, safe by daylight, ceases to be so after dusk. This is the moment when marauders begin their campaigns. And I saw, by the setting sun, mounted sentries, armed to the teeth, stationed at the village gates, near the flocks, on little buttes from which they could survey the crops.

Mogador to Douar Oumbarek ou Dehen

Mogador, whose name is written in large letters on our maps, is far from the significant port we could imagine it to be. The person who would expect to find a city in constant contact with Europe would be disappointed. Especially in winter, the means of communicating are rare and irregular. Only after 45 days did I receive from Paris a response to letters sent the day after my arrival here. This state of things is linked to the fact that Mogador does little trade today: the port no longer does business except with the Chiadma, Haha, Chtouka, and Ilalen tribes, plus the Sahel and Tindouf, and through there, Timbucktu. It has the monopoly on most trade from the Sudan, conducted by the Tajakant. That is the best privilege Mogador has retained. As for the Souss basin, as well as western and central Sahara, from the Oued Aqqa to the Oued Ziz, they make their purchases in Marrakesh, and that capital receives everything from Djedida (Mazagan). The big commercial center of Morocco is Marrakesh: south of the Atlas, Fez provides the flow of the Oued Ziz and the Sahara region to the east of that river; Mogador supplies the Sahel and the small section of the Drâa basin located to the west of the Oued Aqqa. Marrakesh provides for the entire Souss basin, the huge Drâa basin (except for the small reserve we have just done), all the way to those districts irrigated by the right-side tributaries of the Ziz, such as the Todgha and the Ferkla.

As soon as I received the letters I was waiting for from France, I got underway to the south to get back to Tissint. My friend the Hajji had waited for me: this time I traveled alone with him; he had sent his companion home.

14 to 20 March 1884. Leaving Mogador on 14 March, with the son of S. Abd Allah d Aït Iahia, whose father had given him to us as escort, we arrived at the religious residence of the Ksima tribe on the 20th of the same month. Torrential rains that fell for part of this time had hampered our progress; this is why we took seven days to cover a distance that usually only requires four.

Qaçba Beni Mellal to Ouaouizert.

25 September 1883.— Departure at six-thirty in the morning. Three zetats accompany me, one from the Beni Mellal tribe, two from the Aït Atta d Amalou. Ouaouizert, where I am going, is located at the southern foot of the Middle Atlas, which separates the Tâdla plains from the course of the Oued el Abid and whose north slope I have followed since Tagzirt. I therefore have to climb over this range. Its hills are generally steep; as soon as they become gentle enough to support farming, fields cover them and dwellings appear, but these places are rare: almost all the sides are stiff and woody, and except for spaded-out spots, clearings scattered here and there, a thick forest adorns the sides of the massif. Lentisks, carob trees, and pines dominate; they reach a height of five to six meters. The ground is half earth, half rock; the latter not a long bedrock, here, but rather isolated blocks emerging from the earth between trees. Streams with running water irrigate both sides. The road, always mountainous, challenging everywhere, is very difficult in two places: first, upon exiting Qaçba Beni Mellal, at the passage called Aqba el Kharroub; then as we approach the pass, Tizi Ouaouizert, preceded by an extremely steep climb. At one o’clock, I reach Ouaouizert.

No important waterways along the road today. Few people on the road. The dwellings we encountered were very poor in appearance: sometimes small houses, two meters high, built of rammed earth, covered with flat roofs, most of them located halfway up the slope and halfway sunk into earth; and sometimes simple huts of branches; the few douars I saw were made up only of shacks arranged in a circle: no true tents.

Stay in Ouaouizert

Immediately after leaving Qaçba Beni Mellal, I entered into the territory of the Aït Atta d Amalou, in whose lands is located Ouaouizert. They have nothing in common with the Aït Atta of the Drâa, nor with the Berâber. They are a small Tamazight tribe (chleuha), independent, whose borders are: north, the Tâdla; south, the Oued el Abid; east, the Aït Seri; and west, the Aït Bou Zid.

Upon delivering this account into the hands of my readers, as the events that marked my journey and the efforts that accompanied it pass together before my eyes, so many names, things, sensations flock to my mind! Among the memories, both pleasant and painful, that this instant evokes, there is one—of an infinite sweetness—a single one before which all the others fade away: the memory of the men in whom I found kindness, friendship, fellow feeling; those who encouraged, protected, and helped me in preparing my journey as in accomplishing it, and in the occupations following it. Some are French, others Moroccan; some Christian, some Muslim. I pray they will allow me to unite them into a single group to thank them all together and assure them of a gratitude that is too keen for me to express all I feel.

May he whose erudite lessons prepared me for this journey, whose advice guided it, whose care organized its undertaking, receive first of all the homage of my profound gratitude. I speak of Mr. O. Mac Carthy, president of the Société de Géographie of Algiers, the natural protector of whomsoever works toward knowledge or for the greatness of our colony.

The Sires Maunoir and Duveyrier encouraged me before my departure, and greeted me upon my return. The brilliant recognition awarded to me by the Société de Géographie, when I had only just returned, is all due to them. I cannot thank them enough for their kindness.

Hajj Bou Rhim, Bel Qasem el Hamouzi, who, at risk to yourself, protected me in times of danger, to whom I owe my life itself, whose distant memory fills me with emotion and distress, where are you today? Are you still alive? Will I ever see you again? How can I express my gratitude—and my regret at not being able to prove it to you?

Finally, let all those whom I have not mentioned—not through forgetfulness but because the list is too long—receive my recognition and thankful homage.

Paris, October 1887.

On the eve of beginning my journey in Morocco, two questions arose: What itinerary should I follow? And what means should I employ, to follow it?

The first question resolved naturally: I would, as much as possible, travel only through lands as yet unexplored and, from among these, choose the most interesting regions, whether for their physical attributes or their inhabitants. After this decision, I determined the following itinerary:

Tangiers, Tetuan; from there, to Fez via a more easterly route than those taken up to this point; from Fez, into the Tadla across the mountainous massif occupied by the Zemmour Chellaha and the Zaïan; travel through the Tadla to the Oued el Abid, passing through Demnat; cross the High Atlas east of the peaks already explored, reach the Moroccan Sahara and chart as well as possible the vast portion of it that remains unknown, that is, the southern side of the Anti-Atlas and the region between this chain, the Oued Drâa and the Sahel; then see the high basin of the Drâa and the tributaries on the right-hand side of the Ziz; from there, return toward the Algerian border, across the High Atlas a second time and along the course of the Oued Mlouia; then the final stages, Debdou, Oujda, and Lalla Maghnia.

This was the goal I put forward. There remained the second question: by what means could I achieve it? Could I travel as a European? Or would I need a disguise? There was good reason to hesitate; on the one hand, I found repugnant the idea of passing myself off as something I was not; on the other, the foremost explorers of Morocco, René Caillié and Mssrs Rohlfs and Lenz, had always traveled in disguise and declared this precaution indispensable. That opinion was shared by many Moroccan Muslims whom I consulted before my departure. I reached the following compromise: I would leave in disguise; once underway, if I felt my disguise necessary I would maintain it; if not, I had only to chuck it aside.

This first point decided, I needed to choose from possible disguises. There are only two religions in Morocco. I must belong to one of them.