COOK THE COCONUT PALM IN AMEKICA. 325 



Warburg includes Cocos nucifera in a list of " all-tropical shore- 

 plants " (Litoral-Paniropisten) that have pronounced adaptations for 

 swimming (ausgepraegten Schwimmanpassungen) . The adaptations 

 are specified as " swimming-tissue in the husk and empty space in 

 the kernel" (Schwimmgewehe im Mesocarp und Hohlraum im Endo- 

 sperm). a 



It is true that the coconut is provided with a tough, fibrous husk 

 from an inch to 2 inches in thickness which enables it to remain afloat 

 for a long time. There is even a layer of wax on the surface, as 

 though to render it impervious to water. A contrivance better 

 suited for the maritime distribution of the nut would be difficult to 

 imagine, and it is not surprising that writers who approach the sub- 

 ject from the standpoint of structure alone should continue to rely 

 on apparently indubitable proof regarding the true habits of the plant 

 in nature. 



Unfortunately there appears to be no direct evidence to support 

 these deductions from the structure of the coconut and its powers of 

 floating. The same general type of husk is to be found among scores 

 of other related species of palms, which do not grow on seacoasts and 

 are not distributed by water. That the husk of the coconut is thicker 

 than that of the other related species but comports with its larger size 

 and the greater danger of breakage when it falls to the ground. 

 The waxy coating of the surface is also no unique character, but is to 

 be found in well-nigh the whole group of palms, the small fruits of 

 many inland species being far more waxy than the coconut. 



In the East Indies, where the culture of the coco palm has reached 

 its highest development, nuts intended for planting are picked from 

 the trees and let down carefully to avoid injury, even to the external 

 coat of the husk. The breaking of this is thought to reduce mate- 

 rially the chances of successful germination. To permit the husk to 

 dry out or to become infected with putrefactive bacteria or fungi 

 might be equally dangerous for the young plant. 



The unique habit of the coconut of preserving a store of water in an 

 interior cavity of the seed is in itself an indication that the species 

 was native in some relatively dry interior region where the regular 

 supply of moisture from external sources would not suffice for ger- 

 mination. These extensive provisions for water storage would seem 

 superfluous in a maritime plant able to draw moisture from sandy 

 beaches wet twice a day with tidal brine. The distance to perma- 

 nent moisture on a sandy ocean beach is very short; in fact, the 

 sand is never really dry at all except at the surface. For a plant able 

 to thrive on a salt solution, a covering of an inch or two of sand 



"-Warburg, 0., Einige Bemerkungen Ueber Die Litoral-Pantropisten, Annales du 

 Jardin Botanique de Buitenzorg. Supplement II, p. 133. 1898. 



