Longevitif oj Seeds. 189 



acid to adhere to the seed, which, is easily avoided by thorough 

 washing, followed by treatment with dilute ammonia or lime 

 water, aind repeated washinj;. If then dried the seeds, whether 

 Acacia, Clover, Broom, Gorse, or the like, are ready fur planting 

 and immediate "germination. If the washinjx and dryinjr are 

 rapidly done the seeds do not swell, and will keep fairly well, 

 whereas seeds softened by hot water nmst be {ilanted at once. 

 In dilute sulphuric acid the uncuticuhvrized seeds soon lose the 

 power of germination, and the cuticularized ones remain unsoft- 

 ened. Hence the acid rnust only be applied to drj^ seeds. 



The length of treatment with acid depends upon the extent to 

 which the cuticle is developed, and as this varies in different 

 saimples of seed from the same plant, sample tests should be made 

 before treatment, and the acid only used when the percentage of 

 hard seeds is considerable. General data for different seeds are 

 given in the main list, but a few detailed datai for samples of 

 very hard seed are given here, the usual washing and soaking in 

 water following treatment with acid : — 



Acacia dealhata. 



8 p. c. swelled in 2 days. 



,, ,, ,, in water. 



„ „ „ ,, 70 p. c. 



gern)inated. 

 ,, 6 ,, - 92 p c. svvelh'd in 2 days in water, 72 p. c. 



germinated. 



After 6 hours some of the integuments wei'e e^jten right 

 through, and the embryo exposed on washing, but such seeds 

 may still be capable of germination in a germination chamber, 

 though few would survive in the soil. 



Similar results were obtained with samples of old very hard 

 seed of -.4. longifnlia and A. decurrens. For the smaller seeded 

 Acaciais, such as Acacia moiitana, A. leprosa, etc., 1 to 3 hours, 

 and for such forms as A. irrutnflua, 2 to 4 hours in suljjhuric 



