THE SHRINKING AND SWELLING SEED 195 



We there have genera, like those of Calotropis and Gossypium, 

 where the hairs may form a quarter or even nearly half the 

 weight of the seed ; and, as in one species of Gossypium named 

 in the table, the hairs may be heavier than the kernel. 



In illustration of the effect of large wing-like appendages (B) Wings, 

 on the relative weight of the seed-coats, I will take the seeds 

 of three familiar tropical plants, Swietenia Mahogani, Moringa 

 pterygosperma^ and Tecoma stans^ the data for which are given in 

 the following table. 



Table illustrating the Effect of Wings on the proportional 

 Weight of the Seed-coats in Resting Seeds. 



Note, — In Pinus the seed is only partially enclosed in the base of the wing, and is 

 exposed on one side. 



