28 BULLETIN 123, U. S. DEPARTMENT OF AGRICULTURE. 
Cassava, or manihot, a semitropical plant used for food in the West 
Indies, Central and South America, is now cultivated in Florida. 
The roots are rich in starch. There are two principal types of the 
plant, the bitter and the sweet. The first is commonly grown in the 
Tropics and requires a longer season than the other, but produces a 
greater yleld. The bitter cassava grown in Brazil contains more of 
the volatile poison found in this family of plants, but this is dis- 
sipated by heat and the washing of the grated roots. The sweet 
manihot is cultivated in some of the Southern States, but mainly for 
starch to be used for finishing in textiles and in other industries. 
From both varieties tapioca of various forms is made, as is also the 
cassava bread which is so common in tropical countries, and which 
is found in many city shops under the name of cassava cakes. 
Arrowroot is the fine starch obtained from various tropical roots, 
and owes its name to the fact that the pounded roots were applied to 
swellings for poisoned arrows. The best arrowroot comes from 
Bermuda and the West Indies. In Europe it is popularly supposed 
to be the most digestible form of starch, and is much used for in- 
fants and invalids, as well as in fine puddings and similar dishes. In 
the United States cornstarch, the “corn flour” of English cooks, is 
more generally used. 
Sago may be properly studied in connection with tapioca, arrow- 
root, and similar starches, as its use is very similar, but it is the 
product, not of a root or tuber, but the pith of a palm tree. The 
trees are cut and split; then the starch is washed, dried, and granu- 
lated. Fifteen years are required to grow a palm yielding 500 
pounds of sago. The tree must be cut before blossoming. If time 
permitted, it would be interesting to study other palms which yield 
food products, especially the “cabbage palm” and those producing 
coconuts. : 
The principal food substance derived from all these underground 
stems is the starch which has been thus stored up for the next genera- 
tion of the plant’s life. Starches from different plants or plant 
parts differ in the form of the starch grain and can be identified by 
the aid of the microscope, but from the culinary standpoint they are 
practically interchangeable, and one form of starch may be substi- 
tuted for another in nearly every case. The yam or a dish of rice 
may be substituted for the potato as a vegetable, or starch from the 
potato, or corn, or wheat, or rice may be used for thickening gravies 
or making puddings, slight changes being made in proportions, 
according to the expansive powers of each kind. 
Starch cookery is a very important subject. That starch may be 
cooked it is essential that every starch grain be brought into con- 
tact with water of at least 140° to 178° F. A careful study of starch 
