A PEEP AT THE TROPICS 251
(See map. Fig. 136.) This grassland zone of the rainy season and the dry season is a latitude of famine for the reason that the tropic rainfall is the most unreliable in the world. An examination of the distribution of rain by months (Fig. 135) shows how difficult is the problem of growing a cereal, which is at the present the chief dependence of the people. When should they plant it? The rainfall is so unreliable that they may plant two or three times and fail. But an established tree can wait for rain and use it when it does come and therefore has a better chance of harvest than an annual crop like sorghum, millet, and corn. Especially would this be the case with an extensive use of water pockets such as are used in connection with the rubber in Malaysia. (Pages 244-245.)
FORAGE CROPS—BEANS (GRAIN SUBSTITUTE )—SOME EXAMPLES
There are many tropical trees producing beans whose forage value and use are much like the honey locust and keawe. For example, babul is the most widely distributed tree in India. I saw babul trees in my first moments in India as I landed on the coasts of Coromandel from Ceylon. They were growing in white sand. I saw them at the foot of the Himalayas clinging to rocky slopes and again at the extreme west as I neared the port of Karachi.
Everywhere the goat herder leads his flocks to these trees. Often he cannot wait for the beans to fall, but with a long hook he cuts down branches that his wards may eat the beans and also the leaves of the tree. In a year of bad drought these trees will be thus beheaded by the million. Often they stand in land too dry for dependable agriculture.
The gigantic saman tree of India yields sugar beans greedily eaten and said to improve the quality of milk.
In Cuba the guasima is left when pastures are being cleared exactly as persimmons are left in the pasture fields of Georgia.
