THE POTATO. 



125 



Colour of Flowers. — These may be white, rose, rose- 

 lilac, rose-purple, purple and violet. 



The depth and number of eyes vary considerably in the 

 different strains. Those having shallow and few eyes are most 

 sought after. 



Classification According to Maturity. — The following 

 are the principal varieties grown in the Union — viz. : — 



Early , about 90 days : Epicure, Early Rose and Early 

 King. 



Medium — 90 to 110 days : Flourball, Factor, Arran Chief 

 and Arran Comrade. 



Late — 110 to 130 days : Up-to-date, Five Towers and 

 Scottish Triumph. 



New varieties, as the old sorts become less popular, are 

 constantlv being introduced, e.g., Kerr's Pink, King Edward 

 VIL, etc. 



Structure and Composition of the Tuber. — Four 

 distinct zones are found in the tuber. " The outer skin is 

 the coloured portion and may be completely separated from 

 the part underneath. The cortical or fibro-vascular layer lies 

 next, and is easily distinguished by the separating line of 

 vascular bundles. In the interior the inner medullary layer 

 appears like an undeveloped stem branching out towards the 

 eyes." 



Composition of the different zones of the potato tuber : — 



The water and nitrogen contents increase from the outer 

 to the inner zones, while the starch content decreases." 



The average composition of the potato is very similar to 

 that of the soft wheats, and is composed as follows : — 



