52 AGRICULTURE IN THE TROPICS [PT. II 



The poisonous juice is often boiled down in the West 

 Indies, until it forms a treacley compound, which is highly 

 antiseptic and is known as cassareep. It may be used for 

 preserving meat, and is an ingredient in many sauces. 



The tapioca of commerce (mostly exported from Singapore) 

 is the starch of the tubers, heated so as to burst the grains. 



Sweet Potato (Ipomoea Batatas). This is another very 

 common vegetable in the tropics, as in the United States, 

 and is one of the best of culinary vegetables. It occurs in 

 very numerous varieties, and is specially popular as a rotation 

 crop in rice fields. It is a small climber, not unlike a true yam 

 in habit, and is cultivated in the same way, and the tuberous 

 roots eaten. 



Arrowroot (Maranta arundinacea). Though the best arrow- 

 root of European commerce comes from Bermuda, the plant is 

 usually a tropical cultivation. The tuberous root-stocks are 

 full of starch, and the plant is cultivated like Cassava. 



Sago. The sago palm (Metroxylon Rumphii and other 

 species) is an important cultivation in the Malayan region. It 

 is a short palm, which only flowers once, as do so many palms, 

 after a long period during which it is saving up food material 

 with which to do so. Just before the flowering stalk arises, 

 the stems are cut, and their pith, which is very rich in starch, 

 scraped out and washed. 



Aroids. A good many members of the family Araceae or 

 Aroideae are also used as food, especially in the strictly equa- 

 torial regions. Perhaps the most important are the taro 

 (Colocasia esculenta) of the East Indies, and the tanier 

 (Xanthosoma spp.) of the West Indies. 



Food for Animals. The cultivation of fodder plants is 

 hardly yet a definite industry in the tropics except in India, 

 where considerable areas are cultivated in Guinea corn, millets, 

 and other plants for fodders. But many of the cereals cul- 

 tivated, and especially the dry grains, furnish good fodder. 

 Large areas of Cuba and of other countries are now under 

 Guinea grass and other fodder grasses. An important minor 

 industry in Ceylon and other places is the cultivation of 



