PERMEABLE AND IMPERMEABLE SEEDS 75 



The detached shell-like coverings of the seed of Guilandina 

 bonducella possess the same quality. of ultra-dryness and display 

 the same absorptive capacity in air as the bared kernel, though 

 to a less degree. They exhibit the relation between the water- 

 contents which we might have expected, the larger water-per- 

 centage of the seed-coverings being associated with a smaller 

 absorptive capacity in the air as compared with the kernel. 

 These qualities are well brought out in the tabulated results 

 given below of an experiment in Grenada in which the shell 

 and the kernel of several seeds were equally divided in each 

 case between two samples, so that the air exposure and oven- 

 tests were applied to truly mixed samples. It may here be 

 added that, as in the case of the kernels, the detached shell re- 

 tains its excess for a long period, though in a diminishing ratio. 

 In one experiment, after a lapse of twenty-one months it still 

 weighed 6 per cent, heavier than when first removed. 



COMPARISON OF THE ABSORPTIVE CAPACITIES IN AIR WITH THE WATER- 

 CONTENTS OF FRESHLY BARED KERNELS AND OF THE DETACHED 



SEED-SHELLS OR COVERINGS OF GUILANDINA BONDUCELLA, THE 

 SAMPLES BEING TRULY MIXED, AS ABOVE DESCRIBED. 



The shell or 

 covering of 

 the seed of 

 Guilandina 

 bonducella 

 has the same 

 quality of 

 ultra-dryness 

 and the same 

 absorptive 

 capacity as 

 the kernel. 



We are thus brought face to face with the curious cir- 

 cumstance that if we break open one of the seeds of 

 Guilandina bonducella and allow it to remain in this condition 

 for a few days it will increase its weight on the average 

 by 1 1 or 12 per cent. It is essential to break through the 

 seed-shell, it being immaterial whether the shell is in a few 

 or in many pieces, or whether the kernel is left whole or 

 in fragments. 



