l;U BOARD OF AGRICULTURE. 



by the roots and lonves. Tlicy differ from the true roots in perform- 

 ing no i):irt in <;;atlu'ring material for tiie growth of tlie plant. Around 

 tlie thickened stem or tuber are arranged leaf buds which under proper 

 conibtions develop into shoots or stems of the plant. 



The tubers furnish the material for the growth of the new plant 

 imtil the roots and leaves are sufilcientl}' developed for the plant to 

 maintain an independent existence. The potato, like the Indian corn, 

 is one of the few plants that America has added to the cultivated 

 food plants of the world. 



At the time of the Spanish conquests in South America it was 

 cultivated by the natives near Quito. It is said to be native of Chili, 

 Peru, Columbia, Mexico and the southwestern portion of the United 

 States. At what date and b}' whom it was introduced into P^urope 

 is uncertain. 



The potato is mentioned in Spanish books as early as looS, and 

 in English books some ten or twelve years later. Both England and 

 Spain claim the honor of being the first to introduce the potato into 

 Europe. For man}' years it was there cultivated as a curiosity and 

 it is only a little more than one hundred 3'ears that its food value 

 has been generally recognized. 



The general impression is that as a food potatoes are chiefly valu- 

 able for the starch they contain. Good authorities have even gone so 

 far as to make that statement. Possibly this is true in the majority 

 of cases ; but owing to great variabilit}' in the composition of potatoes 

 it is doubtful if it is wise to accept the statement without qualifi- 

 cations. 



Nobbe found in potatoes at the time of planting 



77.79 per cent water, 



1.97 " cellulose, 

 14.91 " starch, 



4.11 " protein, 



1.22 " ash. 



This analysis shows an exceptionalh* large amount of protein and 

 the amount of starch exceptionally small ; yet it serves to illustrate 

 the point that potatoes are not always chiefly valuable for the starch 

 they contain ; for in this case the proportion of protein to starch is 

 greater than in Indian corn. 



The average composition of potatoes is often quoted as being 



about as follows : 



"Water, 75.0 per cent. 

 Protein, 2.1 *' 



