CLUE TO THE HOMOLOGIES OF FRUITS 243 



cases is rather less than half of the seed's length, the chief 

 difference being in the albumen, which is rather mealy in the 

 seeds of the red berry and more fleshy in the seeds of the 

 green berry. Another indication of the contraction of the 

 seed in the moist ripening berry is to be found in the decrease 

 in the relative weight of the coats. Since the coats form 33 

 per cent, of the weight of the entire seed in the green berry, 

 and 25 per cent, in the red berry, we see that these seeds 

 follow the principle laid down for shrinking seeds in 

 Chapter IX. 



The fruits of Tamus communis give us the same indications, (e)byTamus 

 the seeds of the ripe red berries being smaller, less heavy, and 

 rather harder than those of the full-sized unripe green berries. 

 There seemed at first to be an intermediate stage, when the 

 berries assumed a yellowish hue, but this proved to be con- 

 nected with the premature withering of the parent stem. In 

 making such observations it is necessary to compare berries 

 growing on the same branch. The table subjoined gives 

 the average of a large number of weighings and measurements, 

 almost all yielding similar results. 



TABLE SHOWING THE CONTRACTION OF THE SEEDS OF 

 TAMUS COMMUNIS IN THE RIPENING BERRY. 



communis. 



The loss in weight of the seed was about 9 per cent. 



The loss of weight (about 9 per cent.) of the shrinking seed 

 in the ripening berry is not great, and a much greater loss is 

 sustained when the seed is exposed to the air, as is shown in 

 the results given a page or two later. The individual differ- 

 ences in weight and size in the seeds of Tamus communis seem 

 small, but they become considerable when forty or fifty seeds 

 are weighed together or measured in a line. The seeds of 



