375 



Averao'o Xo. of jjlants of cacli race fi.TT 

 Average yield per plant (i lbs. 13 oz. = l].iY.) kilos. 

 Greatest average yield of any race IT ll)s. 10 oz. = 8 kilos. 

 Greatest yield of any plant 'M^ lbs.- '3 oz. = \:].i: kilos. 

 Eate per acre 12623.7 lbs. = 12 cwt. 2 qrs. 23.7 lbs. 

 "Rate per hectaire 2321 kilos. 



Before ooItio- anv fm-ther it is convenient to state the chief 

 characters in which llic races differed from each other, everyone of 

 which must be taken into consideration in building nn a sound 

 scheme of classification, and of which the degrees of importance 

 have to ])o guaged. 



(i) the variation in the colour of the tuber. — whether 

 with magenta sap or without. 



(ii) the variation in the whiteness of the flesh, apart 

 from the masfenta sap, whether ivory white or 

 with an ochre tint. 



(iii) the variation in the consistence of the flesh, 

 (iv) the variation in the length of the tuber, 

 (v) the variation in the nundter of tubers, whether 

 solitarv or twinned or more than twinned, 



(vi ) the variation in the evenness of the tuber, whether 

 branched or not, 



(vii) the variation in the corkiness of the skin, 

 (viii) the variation in the numl)er of rootlets over the 

 surface, 



(i.\) the variation in the |)osition of swelling, whether 

 high up or low down. 



(\) the variation in vield. 



(xi) the variation towards earliness or lateness. 



(xii) the variation in keeping power, whether the tuher 

 can be made to rest or cannot. 



(xiii) the variation in the iiresence of magenta colour 

 in the above-ground parts, 



(xiv) the variation in the size of the frills on the stem. 



(xv) the variation in the production of prickles, 



(xvi) the variation in the outline of the leaf, whether 

 the auricles are rounded or are not. 



(xvii) the variation in the degree of glaucousness at 

 the back of the leaf. 



(xviii) tlie variation in the production of bull)ils. etc., 

 etc, 



