SEED-COLORATION 



399 



The colour of the kernel or embryo in the case of these The colour 

 three red seeds in the resting state varies somewhat. In kernels in 

 Adenanthera pavonina it is yellowish, which indicates that the \^^ seeds of 

 embryo was green in the unripe seed. In Canavalia gladiata osae. 

 it is white. In Abrus precatorius it is tinged yellow outside, 

 but is white on section. 



Before quitting the subject of red seeds I will briefly refer The stages 

 to the stages of coloration of the orange or scarlet seeds of tLi^oaie'^*" 

 Iris fcetidissima, as observed by me during two seasons in a p^^|.°f.^"s 

 wood at Salcombe. All the stages took place in the moist 

 closed capsule long before the fruit dehisced or showed any 

 signs of drying up. Up to the middle of August, when the 

 fruits were dark green and averaged from loo to i lo grains in 

 weight, the seeds were white and soft, with jelly-like contents 

 and no recognisable embryo. After this, as the capsules con- 

 tinued to increase in size the seeds became pale yellow ; but 

 their contents remained unchanged until the end of the month, 

 when they began to solidify. September was principally 

 occupied with the maturation of the seeds and with the growth 

 of the fruit, the seeds assuming a deeper yellow hue. By the 

 middle of October, when the capsules averaged i6o to 170 

 grains in weight, the seeds were solid, of full size, and of the 

 typical orange or scarlet colour. There was not much altera- 

 tion either in seed or fruit after this date, and in the beginning 

 of November the most advanced capsules commenced to 

 dehisce, and the remainder followed during the course of the 

 month. 



It is worth noting that seeds may acquire much of the Thecolora- 

 coloration which they possess as resting seeds whilst their ^hnst^Sie? 



contents are still fluid and before the embryo is formed, contents are 

 _,, . , , , , 1 • n • 1 , , still fluid. 



This would seem to take place chiefly with monocotyledonous 



albuminous seeds of the type below exemplified. Thus, the 



white soft seeds of Allium ursinum, when they begin to ripen 



in the closed capsule, become dark red, though little more than 



bags of water. In the same way, the white soft seeds of the 



green capsules of Iris fatidissima colour yellow as the fruit 



