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THE AMEBIC AX X AT U BALI ST [Vol. L 



gradually change from green to yellow when maturing, 

 while others appear to change very suddenly, but only if 

 plenty of sunlight and no over-supply of moisture is 

 present. This is particularly true of some of the deep 

 orange varieties, such as Spate Gold (P 29). The seed 

 of this variety remains very dark green until the general 

 appearance of the vine leads you to suppose it is ripe, but 

 if plenty of sunlight is present and not too much moisture, 

 and the pods are allowed to remain for a few days, the 

 dark green changes to a very deep orange, and this deep 

 orange is characteristic of Spate Gold when grown com- 

 mercially. 



With the green cotyledon varieties, one is bothered by 

 fading of the green to a sort of washed-out yellow in 

 many varieties, if the vines are not harvested at exactly 

 the right time. Express, Velocity and many of the 

 wrinkled sorts (see Hurst, 1904) are particularly subject 

 to change under these conditions. 



The above mentioned difficulties regarding the proper 

 maturing of pea seed have been considered quite fully by 

 Bateson, Darbishire, Lock, Tschermak and other workers 

 in genetics. Hurst (1904) and Lock (1905) particularly 

 have studied the tendency of certain varieties such as 

 Telephone with green cotyledons to fade easily, even when 

 harvested carefully, but left exposed to light. Bateson 

 and Kilby (1905, p. 58) have studied the so-called "pie- 

 bald" peas (peas with green or yellow cotyledons partly 

 spotted or tinged with both colors) and find them to 

 largely result from environmental conditions such as 

 failure to ripen properly or from bleaching after ripening. 

 "Piebald" peas are characteristic of certain varieties of 

 peas, in which the green fades much faster upon exposure 

 to light or moisture or to both than in ordinary green 

 cotyledon types. "Piebald" peas of one pod, according 

 to Bateson and Kilby, are always tinged on the same sur- 

 face. Injuries causing the death of the cotyledon tissue 

 (Bateson, 1905) (Tschermak, 1902) also are a cause of 

 yellow spots on peas from green cotyledon varieties. 



