282 



STUDIES IN SEEDS AND FRUITS 



Ravenala. 



Its dehis- 

 cence. 



same as those obtained for detached fruits of Iris Pseudacorus and 

 Msmlus Hippocastanum (Horse-chestnut), which dehisced in my 

 room after losing 25 or 30 per cent, of their weight. It has, 

 however, been shown that in both these cases dehiscence occurred 

 in wet moss when drying was prevented, and it is very probable 

 that Mahogany capsules would behave in the same way. 



In the above experiment the fruit was dried in the entire 

 condition. Closely similar results were obtained in drying a 

 fruit that had been taken to pieces. The original total weight 

 of the green fruit was 5576 grains, and the weight after the 

 drying-in-air was completed was 1996 grains, the proportions 

 being as ioo*o to 35*8. 



The dehiscence of the fruits of Ravenala madagascariensis 

 (Traveller's Palm), as observed by me in plants growing near 

 the rest-house on the Grand Etang in Grenada, presents 

 another type of the opening of capsular fruits. We are here 

 concerned with a sub-drupaceous capsule displaying loculicidal 

 dehiscence. Within the outer moist husk is a bony endocarp 

 or " stone," which even in the fresh fruit requires a heavy blow 

 to break it, and is 5 or 6 millimetres thick. The dehiscence of 

 this fruit raises a number of questions which are dealt with in 

 other chapters. Not the least important of them are the propor- 

 tion of parts and their several water-contents, and especially 

 the failure of the young seeds, which is here quite phenomenal. 



With regard to the failure of the young seeds, reference 

 will also be made to the subject in Chapter XVI. Here I will 

 merely allude to it in 'connection with the fruit's dehiscence. 

 The full-sized seeds vary from 9 to 1 5 millimetres in length ; 

 but there is only room in each of the double spaces of the three 

 compartments for from three to five, making a possible total 

 ranging from eighteen to thirty seeds. But even this is often 

 never reached. The fruit figured in Schumann's monograph 

 below referred to probably did not contain more than fifteen 

 seeds. Amongst those fruits examined by me there were not 

 uncommonly only one to three full-grown seeds in each valve, or 

 from three to nine or ten in all. All the rest of the fruit-cavity 



