Towards the end of August the sorghum-harvest commenced with the pulling of the light crop of the four-monthly sort, which had been sown in the latter part of April. But the general ingathering of the heavier varieties, which contribute chiefly to the supply of corn, did not take place until the beginning of December, after the rainy season was over. In Sennaar and Taka, sorghum requires five or six months to come to maturity, but in this district it rarely takes less than eight months. Both the early and late sorts commonly attain a height of nearly fifteen feet; the stalks of the former remain quite green, but the reedy stems of the latter become so strong and woody, that they are used for fences to divide one enclosure from another. Some of the varieties are scarcely inferior to the regular sugar millet (_Sorghum saccharatum_) in producing an abundance of saccharine matter; these are known to the negroes as well as to the Arabians of the Soudan, who chew the straw and so express the juice. The Bongo and the Dyoor express the pulp by means of wooden mortars, and boil it till it has the consistency of syrup. From this concoction I was able to procure a spirit which was far more palatable than what I should have obtained by distilling the sorghum itself. [Illustration: The Deloo.] Both varieties of the common sorghum,[26] which here abound in all their minor differences of colour, shape, and size of grain, yield well-nigh a dozen different descriptions for the market at Khartoom. The standard value is fixed by the Fatareetah, a pure white thin-skinned grain, which also is grown by the negroes in the Seriba. All negro races that depend upon agriculture for their subsistence consider the cultivation of sorghum most important. Of the people among which I travelled, the Bongo, the Dyoor, and the Mittoo, were examples of this. On the other hand, among the southern Niam-niam and the Monbuttoo this cereal is quite unknown. [Sidenote: LIMITATION OF GRAIN PRODUCE.]