342 STUDIES IN SEEDS AND FRUITS 



SUMMARY 



(i) The relation between the number of seeds and the weight of 

 the fruit, more especially for legumes and capsules, is then investigated, 

 increase of size being connoted by increase of weight. In this connec- 

 tion the question is raised as to the stage in which the fruit oft'ers the 

 best materials for such a study, whether as a moist, mature living fruit 

 on the plant, or as a dried fruit of the herbarium. The answer supplied 

 is that dried-up fruits are only of service when referred to the living 

 condition, since a fruit with living pericarp and actively functioning 

 seeds cannot be compared with one where the fruit-case is dried up 

 and dead, and the seeds are in a state of suspended vitality. The 

 comparison can only be made with dried fruits by reconstituting the 

 living condition. 



(2) To determine this relation, however, we are often compelled 

 by the whip of necessity to appeal to the dry fruit ; and the author 

 tabulates the results of a large number of observations on dried as well 

 as on moist fruits. 



(3) Summing up the indications of the influence of the number of 

 seeds on the proportion of parts in capsules, like those of Msculus^ Canna, 

 and Iris, he finds that the fruit, in response to the increase in the number 

 of seeds, whilst becoming larger and heavier, acquires a relatively lighter 

 pericarp. The legume, as typified by the pods of Albizzia Lebbek and 

 Leucana glauca, on which extensive observations were made, follows 

 the principle of the capsule in few- seeded pods. However, in many- 

 seeded pods, as the seeds increase in number and the fruit increases 

 in length and weight, the legume preserves a fairly constant relation 

 between the pericarp and the seeds. 



(4) The indications afforded by other legumes often give no very 

 definite results. This is due in part to the insufficiency of the 

 materials, but partly also to the influence of some disturbing cause 

 which specially affects small pods with few seeds, like those of Ahrus 

 and Ulex, and seems to make each plant a law to itself with regard 

 to the size and weight of the legume and the number of the seeds. 

 This influence is apt to upset all small sets of observations. 



(5) It is in the abortion of ovules and failure of seeds that the 

 cause of this disturbing influence is to be found ; and it is pointed out 

 that the legume would be more likely to be affected than the capsule in 

 this respect, since its growth is mainly in one dimension, while with 

 the capsule the growth is tangential rather than linear. 



(6) As regards the alterations in the average weight of a seed as 

 the seeds increase in number and the fruit increases in size and weight, 

 the indications for the legume are that the seed's weight is but little 



