38 STUDIES IN SEEDS AND FRUITS 



if we except the species of Pithecolobium^ in no instance to the 

 Leguminosae. 



On the other hand, of the seeds of plants to be placed 

 in the " maximum " group, where the increase of weight is 

 1 20 per cent, or more, quite two-thirds are leguminous ; and 

 of these we may cite Adenanthera pavonina^ Canavalia obtusifolia. 

 Cassia fistula^ and species of Entada^ Enterolobium, Erythrina^ 

 Guilandina, Leucana^ Poinciana, etc. Belonging to a variety 

 of other families are the seeds of Barringtonia speciosa, Bignonia^ 

 Ipomcea pes-capr^^ Prifnula, Swietenia (Mahogany), etc., which 

 are for the most part placed here provisionally, since only 

 occasionally, as with the species of Ipomcea, has the germinative 

 capacity been tested for individual seeds of which the shrink- 

 ing has been observed. Several of these probably belong 

 to a type of seeds where the shrinking of detached seeds 

 under experiment is considerably in excess of what takes 

 place in nature. If we were able to interrogate nature 

 more closely, we should probably find that the " maximum " 

 group would be almost entirely leguminous, thus justifying 

 the original view of Nobbe, which is referred to a few 

 pages back. 



We can now turn from the range of extreme groups to 

 that of different species. Here we can cite as extreme cases : 

 (a) On the " minimum " side, the seeds of Ricinus communis, 

 which require to absorb only 33 per cent, of their 

 weight in order to germinate, and the grains of 

 Millet {Panicmn miliaceum), which only increase their 

 weight by 25 per cent, when swelling by water- 

 absorption ; 

 {b) On the " maximum " side, the different leguminous 

 seeds that increase their weight from 150 to rather 

 over 200 per cent, in taking up water for germina- 

 tion, such as Canavalia obtusifolia, Entada scandens, 

 Guilandina bonducella, and Leucana glauca. 

 There is this much to be said concerning all cases where 

 the amount of water absorbed for germination is very small, 



