222 STUDIES IN SEEDS AND FRUITS 



(I i) Although, as established in Chapter II., the seed when swelling 

 for germination regains approximately the water lost in the shrinking 

 process, or, in other words, returns to about its original weight in the 

 pre-resting state, it is shown that this result is in a sense accidental, 

 since the . coats do not win back all the water they gave up in the 

 shrinking stage, whilst the kernel takes up as a rule considerably more, 

 the two results going to counterbalance each other in determining the 

 ultimate swelling weight (p. 199). 



(12) The materials for constructing the shrinking and swelling 

 regime for a considerable number of seeds are then tabulated and 

 explained. Commencing with a typical impermeable and a typical 

 permeable leguminous seed, it is shown that in both cases the coverings 

 of the sweUing seed fail to regain all the water lost in the shrinking 

 process, the deficiency being greatest with the permeable seed. On the 

 other hand, the kernel in both cases ultimately holds more water than in 

 the pre-resting state. The same principle, it is pointed out, applies 

 generally to leguminous seeds ; but by the employment of the additional 

 materials we are enabled to see a little more into the average details of 

 the processes. As a general rule, although the coats of the permeable 

 seed shrink more than those of the impermeable seed, both double their 

 weight in the swelling process ; whilst the kernel of the impermeable 

 seed shrinks more and increases its weight threefold as compared with 

 the kernel of the permeable seed, which shrinks less and only doubles 

 its weight when swelling for germination (p. 200). 



(13) It becomes apparent from all the tabulated results that the 

 resting state leaves its impress on the seed swelling for germination, 

 especially with regard to the coats. This is also evident in the contrast 

 in appearance between the drier, tougher, and relatively unyielding 

 coverings of the seed swollen for germination and the moister, softer, 

 and more yielding coats of the pre-resting seed. But it becomes 

 particularly noteworthy when we find that the seed on the point of 

 germinating is a little smaller than the so-called unripe or pre-resting 

 seed (p. 204). 



(14) The result is that conditions of strain arise within the swelling 

 seed. Whilst with the pre-resting seed the kernel lies easily within 

 its coverings, with the swollen seed ready for gecmination the kernel 

 holds considerably more water than in the pre-resting state and lies 

 constrained within its tightened, unyielding coats. Examples of the 

 strain within the seed thus produced are given, and it is shown that 

 within its tightened envelopes lies a kernel on the average morfe than 

 20 per cent, heavier through water-absorption than in the pre-resting 

 state. The result is the rupture of the coverings, the process being 

 purely physical and not necessarily succeeded by germination (p. 205). 



(15) That the seeds of other orders may possess a regime similar to 



