They have a great number of monks and priests, each of whom is called a Lama. The principal one is the Dalai Lama, in Lhasa, but almost on a par with him is the Tashi Lama, the head of Tashi-lunpo, the large monastery at Shigatse. The third in rank is the High Lama at Urga in northern Mongolia. These three and some others are incarnated deities. The Dalai Lama never dies; the god that dwells in him merely changes his earthly body, just as a snake when it casts its skin. When a Dalai Lama dies it means that the divinity, his soul, sets out on its wanderings and passes into the body of a boy. When the boy is found he becomes the Dalai Lama of Lhasa. Lamaists believe, then, in the transmigration of souls, and the end, the fullest perfection, is peace in Nirvana. There are many monasteries and nunneries in the upper Brahmaputra valley. The temple halls are adorned with images of the gods in metal or gilded clay, and butter lamps burn day and night in front of them. Monks and nuns cannot marry, but among the ordinary people the singular custom prevails that a wife can have two or several husbands. Among Mohammedans the case is just the reverse: men can have several wives. ATTEMPT TO REACH LHASA It was from Lop-nor in the year 1901 that I penetrated into this lofty mountain land for the third time. The summer had just set in with its suffocating dust storms, and we longed to get up into the fresh, pure air. The caravan was large, for I had sixteen Mohammedan servants from Eastern Turkestan, two Russian and two Buriat Cossacks, and a Mongolian Lama from Urga. Provisions for seven months, tents, furs, beds, weapons, and boxes were carried by 39 camels, 45 horses and mules, and 60 asses; and we also had 50 sheep for food, several dogs, and a tame stag. When all was ready we set out towards the lofty mountains and crossed one range after another. When we reached the great heights the caravan lost strength day by day. The atmosphere is so rare that a man cannot breathe without an effort, and the slightest movement produces palpitation of the heart. The grazing becomes more scanty the higher you go, and many of the caravan animals succumbed. At last we seldom travelled more than twelve miles in a day.