THE SHRINKING AND SWELLING SEED 207 



seeds, usually of the variable type, the tension produced during 

 the swelling of the resting seed is but slight, as with those of 

 Entada polystachya and Poinciana regia. In other variable seeds 

 again, as with those of Cassia fistula, the strain may be great ; 

 whilst in rare instances, as with the seeds of Bauhinia, there 

 may be none at all. The case of Cassia fistula is interesting, as 

 it indicates that albuminous seeds may behave like exalbuminous 

 seeds in this respect. 



Be 



This is all that can be said here for the combined shrinking 

 and swelling regime of leguminous seeds, and the data in the 

 general table before given must be allowed to tell their own 

 story in individual cases. The reader can work out for himself 

 the regime of any particular seed. Should he wish to contrast 

 the impermeable and permeable types in the same species, he 

 will find in the cases of Dioclea and Entada that the permeable 

 seed in its behaviour, strictly speaking, comes between 

 the two. 



But the seeds of other orders may behave like leguminous 

 seeds when shrinking before entering upon the rest-period 

 and when swelling previous to germination. What we may 

 term the convolvulaceous regime, as exemplified in the The con- 

 behaviour of the two species of Ipomxa illustrated below, does rlghjj|'.*^^°"^ 

 not seem to differ materially from the leguminous regime, 

 although the seeds themselves differ much as respects the 

 albumen, embryo, and other characters. In its conspicuous 



