THE SHRINKING AND SWELLING SEED 197 



fruit would be transported, as I find, only a few paces ; 

 but during a strong gust I have known it to be carried a 

 hundred feet. 



In this connection the remarks of Dr Goebel on the Goebel's 

 " parachute-apparatus " of fruits are well worth quoting, since cinrefning 

 they would apply in a sense also to seeds. In his Organo- '''"*^- 

 graphy of Plants (English edition, ii. 570), he writes as 

 follows : — " . . . Many arrangements which have hitherto 

 been considered merely as a parachute-apparatus on the 

 ripe fruit are in my view to be considered as a trans- 

 piration-apparatus for the ripening fruit, and these sub- 

 sequently can be used for distribution, but are not necessarily 

 for this. . . ." However, the function of the wings of 

 the moist seed in the living fruit would probably be 

 haustorial. In other words, these appendages would greatly The author's 

 increase the seed's capacity for absorbing water. In the cernii^*^°"" 

 instance of the moist white seeds of the Mahogany tree the f^®t"^Vb"*' 

 increase of the area of the receiving or absorbing surface due Mahogany 

 to the wing is very large, the alar surface-area being more than 

 double that of the seed, as is Indicated in the following 

 measurements : — 



Surface-area of the seed without the wing, 450 square millimetres. 



wing alone, 1050 



winged seed, 1500 



„ winged seed, 1500 „ 



In the case of the seed of the Pine it was long ago 

 suggested by Goeppert, as quoted by Nobbe in his Handbuch 

 der Samenkunde (p. 49), that the wing exercised the function 

 of a funicle or umbilical cord. 



With the Mahogany seed it is probable that in the closed 

 living fruit the wing also serves for storage of water. As 

 shown in the tabulated results of my observations given 

 below, the wing and coverings of the soft white seed in the 

 full-grown fruit hold nearly twice as much water as the 

 kernel, losing about 89 per cent, of their weight in the 

 drying and -shrinking process, as against 49 per cent, lost by 



