THE PROPORTION OF PARTS IN FRUITS 329 



(9) This occasional tendency of a seed to continue its growth 

 after the fruit-case or pericarp has begun to dry, or, in other words, to 

 die, finds its final expression in the germination of the seed on the 

 plant. To put it in another way, it is a step towards vivipary. 



(10) Reference is then made to the principle established by the 

 results tabulated in this chapter, that as the fruit grows, matures, and 

 dries, the proportion by weight of the pericarp decreases and that of 

 the seeds increases. This is merely stating in other words the familiar 

 fact of observation that the earlier history of a fruit's development is 

 mainly concerned with the fruit-case and the later history with the 

 seed. As illustrating this principle for the legumes, the pods 

 of the Scarlet-runner [Phaseolus multiflorus) and of the Broad Bean 

 [Faba vulgaris) are specially discussed, the fruits of Iris Pseudacorus being 

 taken for the capsules, whilst the acorn is also referred to. Small 

 departures from this rule are noticed in the cases of the coco-nut and 

 of the fruits of Iris fxtidissima and Barringtonia speciosa (p. 315)' 



(11) Attention is then called to the significance of the fact that in 

 the drying fruit the pericarp loses far more water than the seed, the 

 result being that whilst the fruit-case dies the seed lives. Whilst on 

 the average the pericarp of the moist fruit loses between 75 and 80 

 per cent, of its weight, the seed as a rule loses only half its weight 

 (p. 318). 



(12) When we compare the different fruit-types we find that it is 

 in the behaviour of the pericarp in the drying process that most varia- 

 tion is displayed, the seeds being much more constant in this respect. 

 Thus on the average fleshy capsules and pulpy berries lose 86 per cent. 

 of the weight of the moist pericarp when drying on the plant, fleshy 

 drupes 75 per cent., legumes 73 per cent., woody capsules 63 per cent., 

 and palm fruits 62 per cent (p. 318). 



(13) A method of numerically formulating the drying rdgime of 

 fruits is then described and illustrated, and in a special table are 

 given the elements of this determination for nearly sixty plants (p. 322). 



