THE THREE CONDITIONS OF THE SEED 51 



Sometimes these deviations from the normal behaviour of 

 a seed become fixed ; and Nature then facilitates our inquiries 

 by presenting in the same species two types of seeds which are 

 distinguished not only in size and colour, but also by their 

 different degrees of impermeability. Such seeds have also 

 two corresponding degrees of swelling capacity, the permeable 

 seeds requiring much less water than the impermeable seeds. 

 Entada polystachya, as observed by me in Grenada, is a case of (c) Entada 



, ' •' . , r polystacnya, 



this kind. Here we find two types of seeds differing from which dis- 

 each other in almost aU the critical points that distinguish s^eprii- 

 permeable and impermeable seeds, and equally capable of ^Jf^^of 

 reproducing the plant. As indicated in the table below, they seeds, 

 differ in colour, size, and weight, as well as in their swelling 

 capacity, the permeable seed increasing its weight by about 

 124 per cent, before germination, whilst the impermeable seed 

 requires more water and adds 1 50 per cent, to its weight. 



Comparison of the two Types of Seeds produced by 

 Entada polystachya 



Different hypotheses present themselves in explanation of 

 this relation between the swelling capacity and the permeability 

 of a seed. For example, it may be suggested that it is merely 

 a matter concerned with the water-contents or hydratation of a 

 seed, a view that would accept, without explaining, the impli- The question 

 cation of these experiments, that impermeable seeds contain bil^Si^im- 

 less water than permeable seeds. To form an opinion now ^f^^^*^ 

 would be to prejudge a matter which wiU prove to be far more way. 



