284 Subtropical Vegetable-Gardening 



is often difBcult to distinguish between the two. The 

 characters that are marks of distinction in one locality 

 do not seem to apply in another place. 



The bitter varieties contain so much hydrocyanic 

 (prussic) acid in the substance of their roots, that they are 

 poisonous, and cannot be fed to animals ; neither can they 

 be used as food until the roots have been grated to meal 

 and the juice squeezed out. The meal must be well 

 dried on hot iron plates, and it then forms the staff of 

 life in much of South America. Pressed into large thin 

 biscuits and cooked on hot iron plates, it forms cassava 

 bread, which has a peculiar appetizing flavor of its own. 

 The starch which settles from the juice is also heated on 

 iron plates, and is then well known as tapioca. 



The roots of the sweet varieties of cassava, on the other 

 hand, contain hydrocyanic acid, in quantity, only in the 

 rind. The roots, stems, and leaves may be fed raw to 

 farm animals. The peeled roots may be cooked and used 

 hot as a vegetable, forming a cheap food in tropical 

 countries. However, cases of poisoning sometimes arise 

 from mistaking the bitter for the sweet cassava. 



The sweet cassava roots are used to a considerable 

 extent as a vegetable in the West Indies and other tropical 

 American countries. The bitter cassava is well worth 

 raising for the sake of the biscuits, which are most whole- 

 some and appetizing. 



Cassava is grown from short pieces of the thick stems, 

 which are planted 4 to 6 feet apart each way in a well- 

 drained soil. The planting is done in subtropical regions 

 as early in the year as possible, and in the tropics during 

 the cool season. In eight to twelve months the roots are 



