SEED-NUMBER AND FRUIT-SIZE 339 



Summing up the indications of the influence of the number Summary 



of seeds on the proportion of parts in capsules and legumes, tions of the 



we find that the capsule, as illustrated by the fruits of Iris, ^g^nu^ber 



Canna, and ^sculus, in response to the augmentation of the of seeds on 



1 r i ■ 1 • 1 1- 1 • T^i the fruit m 



number or seeds acquires a relatively lighter pericarp. Ihe the case of 



fruit increases in size and weight ; but this increase is due wumes.^ 



more to the seeds than to the fruit-case. The legume, as 



typified by the fruits of Leuc^ena glauca and Albizzia Lebbek, 



follows the principle of the capsule in the few-seeded pods ; 



but in the many-seeded fruits it preserves a fairly constant 



relation between the weight of the pericarp and the seeds, 



the pod increasing regularly in length and weight as the seeds 



increase in number. But the other results obtained for 



legumes often give no definite clue to any such relations, 



except in the case of pods with a few large seeds, as in 



Guilandina bonducella, where the principle of the capsule is 



indicated by both the moist and the dry fruits. This lack of 



relation is partly due to insufficiency of materials ; but in the 



case of small pods with a few seeds, like those of Abrus and 



Ulex, there is evidently some disturbing cause which largely 



counteracts the display of a connection between the number 



of seeds and the size of the pod. The circumstance of the 



growth of the legume being linear, rather than tangential, as in 



the capsule, may help to explain why the first-named is more 



irregular in its behaviour. For this reason also the legumes 



would be more liable to be affected by the abortion of ovules 



and the failure of seeds. 



As regards the alterations in the average weight of a seed The degree 

 with the accession to the number of seeds and with the increase of the weight 

 in the weight and size of the fruit, the results seem to justify f^ttl^l'*"* 

 the following conclusions : — different size 



(a) In the case of many-seeded capsules, like those of Iris 

 and Canna, we find that as the fruit increases in size and the 

 seeds in numb'er, the seeds of Iris increase their weight, whilst 

 those of Canna remain unchanged. But when a capsule 

 matures only one or two large seeds, as with the Horse- 



