THE THREE CONDITIONS OF THE SEED 29 



results given in Tables A and B for the swelling ratios are 

 fairly representative of the relative values of the swelling 

 processes which precede germination in a state of nature. 



It will have been inferred that if the seed in swelling for In the recip- 

 germination takes up the water lost in shrinking, the processes acterofthe 



must be essentially mechanical in their nature. That the 



swelling of a seed is essentially a mechanical process was processes is 



i i- 7 i i T-V XT i i r T.1 involved their 



established by Dr Nobbe in a variety or experiments. Thus, essentially 

 he found that Clover seeds swelled with much the same 



readiness in ordinary pure water as in water that had been 

 previously either oxygenated, or carbonated, or chlorinated 

 (pp. 1 02, 103) ; whilst he showed that the absorbing capacity 

 is largely independent of the retention of the germinating 

 powers, since seeds of Lady's-fmgers (Anthyllis vulneraria\ with 

 a low germinative value (8 per cent.), swelled almost as freely 

 as seeds of which nearly all (86 per cent.) were able to ger- 

 minate (p. 1 14). The swelling of a seed, as he asserts 

 on p. 101, is merely a mechanical process preparatory for 

 germination. 



In the course of my own observations with the balance, 

 there presented themselves a number of other proofs of the 

 mechanical and reciprocal character of the shrinking and 

 swelling processes. These are merely summarised or illustrated 

 in the remarks immediately following, references being there 

 made to where a detailed treatment of the points raised will 

 be found. 



That the increase in weight of a seed in preparing for Additional 

 germination is essentially due to absorption of water is mechanical 6 



indicated: nature of the 



swelling 



(1) By the fact that when a seed on the eve of germination process. 



is dried in air at the ordinary temperature it returns 

 approximately to its original weight as a resting 

 seed ; 



(2) By the circumstance that the weight-relations between 



the kernel and its coats and between the embryo (in 

 albuminous seeds) and the other parts of the seed 



