130 



STUDIES IN SEEDS AND FRUITS 



Additional 

 evidence to 

 show that 

 the absorp- 

 tive quality 

 of broken 

 impermeable 

 seeds is not 

 affected by 

 exposure to 

 a tempera- 

 ture of 100* 

 C. whether 

 in the case of 

 the coats or 

 of the kernel. 



percentage and for the fresh materials exposed to the air in a 

 broken condition : 



' Coats hold 7-6 per cent, of water and gain in weight 

 Guilandina 1 2 per cent. 



bonducella ' Kernels hold 4-2 per cent, of water and gain in weight 

 1 6 per cent. 



Coats hold 13-8 per cent, of water and gain in weight 

 Entada 8 per cent. 



scandens Kernels hold 7-5 per cent, of water and gain in weight 

 12 per cent. 



These two seeds illustrate what is shown by other im- 

 permeable seeds in the table, namely, that the smaller absorptive 

 capacity of the seed's coats is associated with a larger water-per- 

 centage as compared with the kernel. Dioclea reflexa is irregular, 

 however, in this respect. But the behaviour of variable seeds 

 containing a good proportion of impermeable seeds supports the 

 same conclusion. This is shown in the table by samples of seeds of 

 Gesalpinia Sappan, Entadapolystachya, and two species otErythrina. 



In Chapter IV I have already referred to the circumstance 

 that the capacity possessed by impermeable leguminous seeds 

 of considerably increasing their weight when exposed in the 

 broken condition to the air is but little affected by first sub- 

 jecting the materials to a temperature of 100 C. for an hour 

 or two. In that chapter I took the seeds of Guilandina 

 bonducella as a type. Here I will discuss the additional evidence 

 for impermeable seeds of the same order. 



This double capacity was disclosed in a large number of 

 experiments on impermeable leguminous seeds. In the table 

 I have compared the two results obtained for seeds in the broken 

 condition. In one column we have the gain in weight by ab- 

 stracting moisture from the air when the materials are not heated. 

 In another column we have the gain after the materials have been 

 exposed to a temperature of 100 C. Many of the experiments 

 on the absorptive capacity of the unheated and heated materials 

 were carried out on different samples and under different climatic 

 conditions, so that disturbing influences were likely to affect 



