CLUE TO THE HOMOLOGIES OF FRUITS 249 



Observations of this kind extend over a year or two and 

 require a little patience, since the same locality has often to be 

 visited several times, and much also has to be done at home. 



I will now take a fruit intermediate between a capsule and Second, 

 a berry, the baccate capsule of Thespesia populnea, a tropical fap^s'Ses 

 beach tree of the malvaceous order. The full-sized yellowish- illustrated by 



r • 1 J 1 • 1 11 • Thespesia 



green rruit possesses an abundant, thick yellow juice and white, populnea. 



softish seeds. In the next stage it becomes a darker green, 

 the juice becomes scanty, and the seeds shrink a little, harden, 

 and assume a purplish tinge. Then the fruit begins to 

 " brown " rapidly, and its sides collapse ; whilst its seeds also 

 turn brown, and, continuing to dry and harden, ultimately lose 

 about half their original weight when the drying of the fruit 

 is complete. Finally, the fruit breaks down and the seeds are 

 freed by its decay. In the figures 100, 87, and 50, which 

 represent the relative weights of the white softish seed, of 

 the purplish seed before drying of the fruit has actively 

 commenced, and of the brown, hard seed in the fruit when the 

 drying has ended, we have stated numerically the essential 

 stages of the capsule and the berry. The actual weights of an 

 average seed in these three stages would be ^' ^^ 4-8, and 2*25 

 grains. An index of the changes in the fruit is afforded by the 

 changes in the condition of the adherent calyx, which remains 

 moist and green long after the seeds within have begun to shrink 

 and harden, and only begins to wither when the capsule com- 

 mences to " brown " and to lose weight, thus indicating that the 

 first shrinkage of the seed within the still moist fruit, as in the 

 case of the true berry, precedes the active drying of the capsule. 



With the ordinary dehiscent leguminous pod there is Third, 

 quite another regime. In illustration I will first take that po^£Jas"in"^ 



of Casalpinia sepiaria. the familiar "Wait-a-bit" of Jamaica. Caesalpmia 



^ . ^ ^ , . , -^ sepiana. 



The full-sized green pod with its white, soft seeds represents 



the green capsules of the Horse-chestnut and Iris Pseudacorus 



and the green berries of Berberis^ Arum maculatum^ and Tamus 



communis after they have attained their maximum size. In the 



next stage, which corresponds to the ripe berry and the mellow- 



