ACACIA SEEDLINGS. 389 



ACACIA SEEDLINGS, Part III. 

 By R. H. Cambage, f.l.s. 



With Plates XV to XIX. 



[Read before the Royal Society of N. 8. Wales, November 7, 1917.'] 



SYNOPSIS: 



Vitality of Seed in Sea-water. 



Length of Hypocotyl. 



Sequence in the Development of Leaves. 



Simply-pinnate Leaves. 



Number of Pinnae on one Leaf. 



Tripinnate Leaves. 



Descriptions of Seedlings. 



Vitality of Seed in Sea-water. 

 In previous papers on Acacia Seedlings 1 it was pointed 

 out that seeds of Acacia Famesiana had germinated after 

 having been immersed in sea-water for 190 and 405 days 

 respectively. In order to further test the vitality of 

 seeds of this species, which were collected by Sir William 

 Cullen in Central Queensland in July 1914, another seed 

 was planted after having been in sea-water for 839 days. 

 Previous to being planted it was placed in boiling water, 

 and in 17 days the seedling appeared above the soil. 



These experiments demonstrate the possibility of various 

 seeds retaining their powers of germination for a sufficient 

 length of time to be drifted many thousands of miles, pro- 

 vided they found suitable agents of transport. 



A test was also made with seeds of Acacia penninervis 

 var. falciformis, and A. melanoxylon, collected at Jenolan 

 Oaves, at an elevation of about 2,700 feet above sea-level. 



1 This Journal, Vol. xlix, p. 94; Vol. l, p. 144. 



