THE DEHISCENCE OF FRUITS 285 



of comparison excluded, except in one case there explained. 

 In spite of the contrast between the fruits of Momordica and 

 Scilla on the one hand, and those of Swietenia and Ravenala 

 on the other, the driest of these mature fruits contain a 

 large amount of water. 



Notes on the above table. — The total water of the fruit as 

 given in the last column is estimated by applying a correction 

 to the air-dried residue. Although the result is only approx- 

 imate, the limits of error, as will be seen, are small. The 

 water driven off in the oven after living vegetable substances 

 have been air-dried is the water of hygroscopicity possessed 

 in common by both living and dead matter (see Chapter VII). 

 According to my observations, this varies usually from about 

 10 per cent, for air-dried, stony fruits to about 15 per cent. 

 for loose-textured, air-dried fruits, such as ordinary legumes, 

 capsules, and nuts, the seeds being excluded. Thus, in the 

 case of Momordica^ the air -dried residue of 100 grains of 

 fresh material would weigh 6 grains. In the oven, exposed 

 to a temperature of ico° C, this residue would at the most 

 lose 1 5 per cent, of its weight and would be reduced to nearly 

 5 grains, so that the total water in the fresh material would 

 amount to about 95 per cent. In the same way, if, as is 

 probable, the air-dried Mahogany capsule lost 10 per cent, 

 of its weight in the oven, the air-dried residue of 37*4 

 grains out of 100 grains of fresh material would be reduced 

 to 337 grains, so that the total water held by a living 

 Mahogany capsule, excluding the seeds, would amount to 

 66-T^ per cent. 



It will have been gathered from the preceding remarks, 



as well as from the indications afforded in the table just given, 



that when we speak of a capsule as a dry fruit, we have usually 



in our mind dehiscing capsules, which have been more or Dehiscing 



less completely severed from the parent as far as the biological beSfgdead 



connection is concerned. Dehisced capsules now appear as '^J^^^^^^i 



dead or dying- fruits : and although even the toughest and to the 



V , , ij -111 . c herbarium, 



most ligneous among them hold a considerable amount or 



