The intervening plains and valleys are rich in vegetation of every description; trees of colossal dimensions are found, more especially in the khors (the beds of perennial streams), and the thick luxuriant growth is so dense that the rays of the sun cannot penetrate. The soil is exceptionally fertile and rain abundant, consequently for six months in the year the density of the undergrowth makes it almost impossible to traverse these rich valleys; but when the rains are over and the grass becomes dry, it is generally fired, and thus the plains and valleys become passable again. A quantity of the rain from these hills flows into Lake Birket, some passes also into the Khor Abu Habl, which becomes lost in the sand before it reaches the White Nile. The rain from the southern Nuba hills finds its way into the Bahr el Arab. The plains abound with quantities of deer, giraffe, antelope, and wild boar, whilst the woods contain myriads of birds of lovely plumage, and apes and monkeys of every description. During the winter season, elephants were frequently to be seen in the neighbourhood of Delen, which also abounds with snakes, amongst which the boa-constrictor is not uncommon. The population of Dar Nuba, which at one time was considerable, does not now exceed 50,000; the scattered sub-tribes of Baggara, who roam the plains with the Bederieh and Ghodiat Arabs, have decimated the Nubas, and forced those that are left to fly to their mountain recesses, where they eke out a wretched existence, their protection being the inaccessible nature of their retreats. I found the Nubas a pleasant and well-disposed people; indeed, they have the reputation in the Sudan of being the best of all the negroid races; they cultivate only sufficient quantities of corn, sesame, and beans to serve for their livelihood; whilst the wild fruits and vegetables of their country are so plentiful as to furnish almost sufficient food for their maintenance should they be unable to cultivate. They possess numbers of goats and cattle which supply them with milk and butter; they are much addicted to drinking marissa (a kind of beer made from dhurra), and great quantities of this beverage are consumed at their feasts, principally at the feast known as Zubeir. On this occasion men and women drink and dance together; but notwithstanding this unusual familiarity, I never saw anything which might be considered an outrage to society. With the exception of the Khojur, of whom I shall presently speak, and the head sheikh, monogamy is practised. The Nubas are governed entirely by their own traditional laws and customs, the Khojur only intervening in case of necessity. The Khojur is in reality a sort of religious chief, whose power over the people depends entirely on his skilfulness and sagacity. During the time I was in this neighbourhood the Khojur was a certain Kakum, known as "Kakum of Delen."