238 STUDIES IN SEEDS AND FRUITS 



observations indicate in the case of those of Entada scandens 

 that resting seeds, weighing about 400 grains when removed 

 from the pod, may lose about 2 grains during the next 

 few weeks whilst exposed to the free air. Most of this small 

 loss is probably connected with surface moisture, since Entada 

 pods break up into closed joints from which the seed has to 

 be removed. In the cases of the pod of Guilandina bonducella^ 

 which dehisces usually in full exposure to the sun, it would 

 be unhkely that seeds after lying in the gaping pod under 

 such conditions would not have completed the drying process. 

 Coming to permeable seeds of dehiscing pods, I will cite 

 the case of those of Canavalia ensiformis^ which in ten days 

 after collection from the pods lost about 8 per cent, of their 

 weight and then entered the stable hygrometric state. Then, 

 again, the seeds of Casalpinia sepiaria^ which are in some cases 

 permeable and in others impermeable, lost about 10 per cent, 

 of their weight after being gathered from the opening pod. 

 In both these instances of permeable seeds it is highly probable 

 that nature was to some degree anticipated, and that, left alone, 

 they would have completed their drying before detachment 

 from the pod. 



However, the loss of weight experienced by resting seeds 

 or seed-like fruits after they have been collected is often far 

 more considerable than in the leguminous seeds above cited. 

 As Nobbe puts it (p. 382), the process here involved is 

 what the agriculturist would term " sweating " in the case of 

 wheat, and what the forester would call " airing " when gather- 

 ing acorns, chestnuts, and maple fruits for winter storage. My 

 experiments on Acorns {Quercus Robur) and on the seeds of the 

 Horse-chestnut {^/Esculus Hippo castanuni) indicate that they 

 have still much moisture to lose when they are first detached 

 in the " browned " condition from the tree. The Horse- 

 chestnut seed, as it lies on the ground freshly liberated from 

 its fruit, has still to surrender one-third of its weight in 

 moisture to the air before its drying process is complete. 

 The Acorn also, when in the early stage of browning it falls 



