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STUDIES IN SEEDS AND FRUITS 



With regard to the effect of these fungi on the germinative 

 capacity of resting seeds in general, all depends on the pro- 

 tection the seed owes to its coats. With both permeable and 

 impermeable seeds it would seem that the coverings would 

 usually offer sufficient protection until the next germinating 

 season commenced ; but whilst the impervious seeds would be 

 able to withstand the attack for a long period, it is likely that 

 the permeable seeds would succumb before a second oppor- 

 tunity of germinating presented itself. We have just seen 

 that, as ascertained by Gola, mould affects but little the im- 

 permeability of resting seeds, an inference that may be extended 

 to their germinative capacity. With Rape-seed (Saatraps), 

 which had become covered with these growths after being 

 exposed for forty-three days in moist conditions, Nobbe 

 (p. 107) found that 85 per cent, germinated, the germinative 

 capacity of the sample being 99 per cent. Since these seeds 

 swelled in water, they would illustrate the behaviour of perme- 

 able seeds in this respect. 



It would seem, therefore, that the resting seed in its 

 hardened coats is fairly proof against the attacks of mould, 

 and that speculations as to the direct influence of these small 

 fungi on seeds must be restricted to the seed in its unprotected 

 state, as when it is prematurely exposed in the soft condition 

 through the untimely opening of the fruit. Nature usually 

 ensures the safety of the seed by securing that its coverings 

 harden before the exposure to the outer world takes place. 

 As shown in a subsequent chapter, the hardening of the seed- 

 coverings precedes the opening of the fruit, whether moist 

 or dry, whether rupturing through decay or dehiscing in a 

 regular manner. Were it otherwise, propagation by seed 

 would become impossible except in regions where mould and 

 mildew are infrequent. There seems at first glance a special 

 provision here ; but one could read the same into every detail 

 of a plant's life-history. In a world where all is adaptation it 

 seems idle to employ the term at all. Yet in the tropics one 

 would be strongly tempted to use the phrase in this matter of 



