28 STUDIES IN SEEDS AND FRUITS 



the swelling process as a thing apart would have been to 

 ignore its all-important reciprocal relation to the shrinking 

 process. This conversion is easy. Thus, whilst Nobbe states 

 the swelling capacity of Wheat at 60 per cent., and Hoffmann 

 puts that of Broad Bean (Faba vulgaris) at 104 per cent., I 

 should state them as i"6o and 2*04 respectively, the resting 

 seed being I'oo. 



Although there is a distinction to be drawn, as will be 

 subsequently pointed out, between the water required for 

 germination and the water necessary to saturate a seed, seeds 

 under ordinary swelling experiments are apt to strike a rough 

 average of their own by germinating, so that such experiments 

 frequently prove to be germination experiments, in which one 

 has to fix a somewhat arbitrary limit indicating where swelling 

 ends and germination begins. This was in fact an almost 

 invariable rule in my own experiments ; but by placing the 

 seed in its earliest swelling stage in damp moss, excessive 

 estimates were probably avoided. I do not gather that either 

 Hoffmann or Nobbe attached much weight to the distinction 

 between the swelling needed for germination and the swelling 

 involved in saturation. Indeed, the latter expressly states 

 (pp. 119, 120) that the kernels require as a rule to be 

 thoroughly soaked before germination begins. In his care- 

 fully guarded .recorded experiments the seeds were either 

 immersed in water or kept moist by pouring water over them, 

 methods that seem likely to produce excessive estimates. Yet, 

 except in the case of Faha vulgaris^ his results as a rule come 

 near to those obtained by Hoffmann for the same species ; and 

 in spite of the difference in our methods my estimates for 

 Pisum sativum (Pea), Phaseolus vulgaris (French Bean), and 

 Phaseolus multiflorus (Scarlet-runner), are not far separated from 

 those of Nobbe. This will be seen in the comparison made 

 in Note i of the Appendix. As I have said before, the seeds 

 assert themselves in ordinary experiments, and, disregarding 

 divergent conditions, strike out a rough average result for all. 

 For these reasons, therefore, we may, I think, claim that the 



