600 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



outline ; concave or convex ; the eyes on one tuber may be all alike 

 or of different kinds both with regard to depth and shape, &c. 

 Fig. 192 C of tuber 76 shows both a deep and a convex eye ; figs. 192 

 B and E of tubers 21 and 17 show deep triangular and shallow round 

 eyes respectively. 



The second point that stands out clearly is that none of the 

 above-mentioned characters are in any way related or paired. 

 Thus the depth or shallowness of the eye does not occur specially 

 associated with any other character as shown by the following table, 

 and there is likewise no correlation between the kind of skin and the 

 texture of the tuber. 



Table II. 



Deep eyes. Shallow eyes. 



Tuber 

 number 



Weight in 

 grammes 



Number 

 of eyes 



Grouping 



of 

 sprouts 



Skin 

 smooth 

 or rough 



Texture of I 

 the tuber | 



Tuber 

 number 



Weight in 

 grammes 



Number 

 of eyes 



Grouping 

 of 

 sprouts 



Skin 

 smooth 

 or rough 



Texture of 

 the tuber 



12 



58 



6 



tsi ... 



r 



«' 





51 



8 



tsi ... 



m 



f 



14 



74 



8 



t gr ... 



m 



f 



I 



45 



8 



tsi ... 



sm 



f 



21 



85 



6 



t si 1 si 



sm 



f 



II 



65 



7 



tgr ... 



m 



m 



70 



80 



8 



t si 1 si 



m 



til 





55 



9 



t gr 1 si 



sm 



f 



71 



84 



7 



t gr 1 si 



m 



SO 





56 



7 



... lsi 



m 



m 



73 



74 



6 



tsi ... 



m 



m 



40 



58 



6 





r 



m 



76 



98 





tgr lgr 



sm 



so 



5^ 



70 



7 





m 



m 



67 



80 



8 



t gr 1 si 



in 



f 



61 



51 



7 



lsi 



r 



so 



f = firm gr = groups 1 = lateral m = medium r = rough si = single 

 sm = smooth so = soft t = terminal 



C. — Relation of Seed Tuber-size to Leaf-blotch. 



Experiments were made to determine whether the occurrence of 

 bad plants was in any way dependent upon the size and weight of 

 the tubers planted. 



The tubers used in this experiment were selected from those sent 

 to Wisley by Professor E. S. Salmon, in 1911, from Wye, in connexion 

 with the writer's earlier experiments. In all, five lots of three tubers 

 each were chosen in order of weight and the characters of the tubers 

 were recorded (see Table III. and fig. 194) as in Table I. The tubers 

 were planted in pots on February 7, using Wisley garden soil. 



Sprouts had appeared above the soil by February 28 from all the 

 tubes except 1, 3, 6, 7 and 10 (Table III.), but showed no symptoms of 

 yellowness, although this character had appeared in the other experi- 

 ments. Toward the end of March, however, the plants grown from the 

 smaller tubers began to show unhealthy symptoms, which developed 

 during April. In the absence of any visible cause, the foliage tecame 

 yellowish, the leaflets curled with the under surface exposed to view, 

 the ends of the leaflets turned pink, then brown, and finally died, 

 whilst the leaves became variously blotched. The foliage then exactly 



