SEED-COLORATION 



373 



their hue after the fruit opens ; whilst in leguminous pods the 

 seed colouring is practically complete when dehiscence takes 

 place. With Leguminosas this is the general rule whether the 

 pod regularly dehisces, or breaks up into joints, or liberates 

 the seeds by its decay. As further illustrations may be 

 mentioned Abrus precatorius^ Acacia Farnesiana^ Adenanthera 

 pavonina, Canavalia gladiata^ and C. obtusifolia, Dioclea reflexa, 

 Entada^ Erythrina^ Guilandina^ Leucana^ Mucuna^ Phaseolus^ 

 Poinciana regia, Ficia, Vigna luteola^ etc. 



With regard to the question whether seed-coloration is Does seed 

 confined to one or all of the three states of the fruit, the green, take^ palace in 

 the ripe, and the drying, there are so many different determin- *^^ green, 

 ing conditions between one fruit and another that a careful ing fruit? 

 investigation is requisite before one can venture to reply. 

 One would infer after watching the seeds of Vicia darkening 

 in the drying and blackening pod, or the Horse-chestnut seeds 

 as they brown in the drying capsule, that drying is necessary 

 for their colouring. Here we should undoubtedly be wrong. 

 On the other hand, we would conclude after observing the 

 process of seed-colouring in the Blue-bell {^cilla nutans) that 

 the seeds acquire their shining black hue in the moist green 

 capsule. Here we should most probably be right. That the 

 coloration of the seeds does frequently take place in the closed 

 capsule whilst it is still green and moist has indeed been clearly 

 shown a page or two back. But the subject is very complicated, 

 and Nature seems to have done her best to make observation 

 difficult and immediate inferences hazardous, more especially 

 with legumes. Here experiment and observation must go 

 hand in hand. 



In the first place, I will take the colouring regime of the Experi- 

 seeds of S>cilla nutans as disclosed by my experiments on the LSbimenko 

 fruits of the living: plant. When I experimented on these onthecon- 



. ° ^ - ^ ditions in the 



capsules m the summer or 1908, 1 was not aware that similar interior of 



experiments had been made by Lubimenko on the pods of p^c^s'"*"^"^ 



certain leguminous plants, Pisum sativum^ Colutea arborescens^ and 



Lathyrus latifolius, the results of which have since been published 



