426 STUDIES IN SEEDS AND FRUITS 



ing variations in the period of the fruits' maturation relatively 

 to the seed. If the fruit matures early and dries quickly the 

 embryo will not have reached the same stage of development 

 when the rest-period begins as when the fruit matures and 

 dries late. Where the fruit reaches the limit of its growth 

 far in advance of the seed, we might expect the embryo 

 to be small and but partially diiFerentiated. Where the 

 fruit is not so advanced in growth, the embryo would be 

 much more developed when the suspension of vitality sets 

 in. Where matters are reversed and the embryo grows 

 quicker than the fruit-case, as in Avicennia, the plant is 

 viviparous. Here, however, germination is associated with 

 the rupture and death of the fruit-envelopes. The truest 

 form of vivipary, as already observed, is seen in Rhizophora, 

 where the fruit still lives and the seed still grows, the 

 young plant remaining for a long time attached to the 

 parent. 



It lies with the future inquirer to ascertain how the mother 

 plant through the fruit determines the stage at which the 

 rest-period is to be imposed bn the embryo in the seed. Over 

 both seed and fruit, as previously remarked, hangs the fate of 

 ultimate detachment from the parent ; but this fate may be 

 avoided if the two co-operate so that when the fruit is ripe the 

 seeds have already begun to germinate. The seed depends on 

 the fruit and the fruit on the parent plant ; and since the 

 parent has its part to play in determining the relation of 

 growth between the seed and its fruit, it follows that it pas the 

 first word to say in shifting the plane of the rest-perk)d. I 

 may perhaps be allowed to suggest to some investigator that 

 he should inquire into 



{a) The relation between the stage of development acquired 



by the embryo in the resting seed and the time of 



maturation of the fruit ; 

 {b) The relation between the early -and late maturation of 



the fruit (relatively to the seed) and the conditions 



influencing the mother plant. 



