GLOBE VARIETIES 361 



depth than | of an inch below the surface, for, although the so- 

 called ' seed' is of some considerable size, the true seed is small, 

 and has little power to make its way upward if buried too deeply. 

 The amount of ' seed ' used is from 6 to 8 lbs. per acre. The 

 young plants are subsequently 'singled' so as to leave from 10 

 to 14 inches between each plant in the row, the smaller distances 

 being adapted for the long varieties, especially if smaller and 

 relatively more nutritious 'roots' are desired. 



Yield. — The average yield of ' roots' per acre is about 18 to 

 25 tons. 



Composition. — Cane-sugar is one of the chief ingredients in 

 the mangel. The amount varies from 3 or 4 per cent, in the 

 large long red varieties to about 7 or 8 per cent, in the Golden 

 Tankard and well-grown Globes. 



The water-content varies from 86 per cent, in the best kinds to 

 92 in the poorer varieties. Usually they are much superior in 

 composition to turnips, but in damp, cold seasons large roots 

 may be as watery as white turnips. 



Mangels cannot be fed to stock immediately after being re- 

 moved from the land in autumn, as they contain some ingredient 

 which produces 'scouring' in animals ; what the substance is 

 which is responsible for this effect is not clear ; possibly it is 

 a nitrate or oxalate. Nitrates are present in considerable 

 abundance in autumn, but these compounds gradually diminish 

 in amount if the mangels are kept till spring. The injurious 

 substance, whatever it is, disappears to a large extent on keeping, 

 the yellow-skinned varieties are generally ready to feed to stock 

 before the red ones. 



The nitrogenous substances in mangels average about i'2 per 

 cent., of which a little less than half are albuminoids. Several 

 distinct amides are generally present, especially when the 

 'roots' are not ripe. The fibre averages about "9 per cent. 



5. Sugar-Beet. — The name sugar-beet is given to selected varie- 

 ties of mangel which are specially grown for their sugar-content. 



