52 STUDIES IN SEEDS AND FRUITS 



complex than it at first appears. This question of the ability 

 or inability of seeds to absorb water through their coats has 

 been constantly arising in this chapter in connection with 

 other seed -capacities ; and in the particular subject we 

 have just been considering it is manifestly impossible to 

 make further progress until we investigate the nature of 

 the differences associated with the distinction between a 

 permeable and an impermeable seed. At present, there- 

 fore, the question of permeabihty and impermeability blocks 

 the way. We will accordingly proceed to its discussion 

 in the next three chapters. 



SUMMARY 



(i) We deal here with the three conditions presented by the large, soft 

 pre-resting seed, the hardened, contracted resting seed, and the soft, 

 swollen seed about to germinate (p. i8). 



(2) This involves the study of the shrinking and swelling of the seed, 

 processes which are in the main concerned with w^ater-loss and w^ater- 

 gain (p. 19). 



(3) The balance is the instrument of this investigation, and the modes 

 of thus determining the shrinking and swelling ratios are described 



(4) The indications of the single seed, when its history has been 

 follovv^ed in all three conditions, prove that the water lost in shrinking 

 is regained in swelling for germination, and that the swollen seed 

 represents the return to the pre-resting or so-called unripe state 

 (p. 21). 



(5) The same reciprocal relation between the shrinkmg and swelling 

 processes is established by independent observations of the three 

 conditions on a large number of different seeds (p. 22). 



(6) The principle that the water lost in the shrinking process is 

 gained back in the swelling stage was accepted by Dr Nobbe in his 

 Handbuch der Samenkunde^ 1876 (p. 23). 



(7) Tables of the shrinking and swelling ratios are given, the first 

 containing the results of the author's observations, the second those 

 of Hoffmann and Nobbe (pp. 24-27). 



(8) It is then pointed out that the essentially mechanical nature of 

 the shrinking and swelling processes is involved in their reciprocal 

 character (p. 29). 



