232 



STUDIES IN SEEDS AND FRUITS 



that two-year-old seeds display a range of 2-o per cent., and 

 three-year-old seeds i'6 per cent. 



Respecting the diminution of the water-contents in time in 

 the case of the kernels of permeable seeds, I will first take those 

 of Quercus Robur. Here the kernel in the course of time 

 assumes a chocolate-coloured, semi-waxy appearance and almost 

 a stony hardness, changes which begin at the periphery. Of 

 kernels fourteen months old about a third were completely 

 affected. In another third half of the kernel had undergone 

 the change ; whilst in the remaining third the transformation 

 was either in its early stage or scarcely noticeable. Here a 

 mixed sample of the kernels proved to contain 11-3 per cent. 

 of water. Every seed in samples two years old and more 

 displayed the change completed, the water-percentage in 

 kernels two years old being 13*2, and in kernels three years 

 old 12*2. 



So with the old seeds of Msculus Hippocastanum^ it was 

 found that at least for the first three or four years there was 

 no diminution in the water-contents. Seeds bared of their 

 coverings exhibited a water-percentage of 13-6 when eleven 

 months old, 14-4 when twenty-six months old, 12*6 when three 

 years old, and 13*8 after being kept for four years. These 

 seeds, it may be added, do not discolour with time like the 

 seeds of Quercus Robur. As is well known, the seeds of the 

 Oak only retain their germinative capacity for a few months. 

 With those of the Horse-chestnut the period, as shown in 

 Chapter XVIII., is still less. 



Now and then one comes upon old seeds that are as hard 

 and seemingly as dry as a stone, seeds that might almost 

 be taken for fossils, yet in the oven they prove to contain 10 

 or 12 per cent, of water. The old seeds of Grias cauliflora, 

 the Anchovy tree of Jamaica, a myrtaceous tree that flourishes 

 in the lower courses of rivers in the West Indies, offer con- 

 spicuous examples. A very remarkable alteration in texture 

 takes place in the seeds after their death, when the conditions 

 are dry, as on beaches, where they are stranded in quantities. 



