266 STUDIES IN SEEDS AND FRUITS 



water when dried as does the Acorn (^Quercus), the capsule of 

 Viola, and the pods of Vicia and Cajanus. Then, again, it is 

 apparent that several very different causes have combined to 

 produce the same result in the Coco-nut, the Acorn, and the 

 pod of Cassia fistula, all of which lose a similar amount of 

 water, namely, from 60 to 70 per cent, of their weight. Some 

 of these causes will be considered when we come to deal with 

 the relation of parts in a fruit. 



The development of sugars in the ripening berry makes a 

 material difference in the weight of the fruit after it has been 

 dried in air. Elder berries {Samhucus nigra), before the sugars 

 are formed, lose about 87 per cent, of their weight, but with 

 the production of sugar their weight during drying is 

 diminished by only 78 or 79 per cent., the saccharine materials 

 being especially hygroscopic and preventing the complete 

 drying of the fruit. The berries of the Honeysuckle {Lonicera 

 Periclymenum), which, when the sugars are formed, lose about 

 75 per cent, of their weight, behave in a similar fashion. In 

 the same way the ripe fruits of the Gooseberry {Ribes 

 Grossularia) cannot be dried properly in air on account of the 

 abundance of the sugars. The congealed juice that encrusts 

 the surface of the air-dried berry is very hygroscopic. The 

 ripe fruit loses about 85 per cent, of its weight ; but if the 

 sugars are removed by washing, the air-dried materials make 

 up only about 5 per cent, of the weight of the moist berry 

 (see Note ioa of Appendix). The same behaviour is displayed 

 by the berries of Opuntia Tuna (Prickly Pear), which, when air- 

 dried, lose 82 per cent, of their weight, but if the sugars are 

 removed by washing, the dry residue of 1 8 per cent, is reduced 

 to 12 per cent, (see Note iob of the Appendix). 



The seeds of such sugary fruits often remain moist and 

 sticky and require washing for their complete drying. Those 

 of the Pomegranate (Punica Granatum), for instance, never dry 

 properly unless previously washed. A good example of the 

 influence of the sugars on the air-drying of fruits is afforded 

 by the different behaviours of the husky coverings of the ripe 



