phesidext's address. 31 



Mr. K. H. Canibage has recently taken up the study of Acacia-seedlings 

 where Lubbock left off; and, from his extensi\-e knowledge of the Australian flora, 

 sud' of Acacias growing under natural conditions, he is eminently tjualifled to 

 undei'take it. Since 1915, lie has iiublished live instalments of a monograph on 

 "Acacia-Seedlings." which include descriptions and excellent photographs of the 

 seeds, pods, and young seedlings of fifty-five species. This is an excelfent be- 

 ginning of a very important contribution to knowledge, which can only be done 

 properly as he is doing it, with personal knowledge of the jslants under natural 

 conditions, and with adequate material. As it is necessarily a leisure-time study, 

 he deserves, in an especial manner, all the encouragement and help that we can 

 give him. If he will take into consideration the evidence I am now bringing 

 forward, and will modify his terminology accordingly, 1 venture to predict that 

 liis work will become more inspiring and interesting even than it has been. 



Cambage's papers and illustrations show admirably, how promptly the 

 swanii)ing effect of the usurping, euphyllode-produeing tendency takes place in all 

 the eupliyllodineous sjiecies he has described, with the exception of .1. Dielatioxtjlon. 

 This is one of a small group' of exceptional species, which includes ^1. ruhida, 

 and apparently also the non-Australian species, A. heterophi/lla, that is in need 

 of special and detailed study of good series of gradational stages. 



The transition from an abruptly pinnate leaf, or more usually from a bi- 

 pinnate leaf with one pair of pinnae, or sometimes two pairs, to the first complete 

 euphyllode, of seedlings of the euphyllodineous Australian Acacias, may take 

 place on any leaf, from the second to the ninth, or even later, according to the 

 species, and according to circumstances. The difference in seedlings of the same 

 species is mainly due to the absence or the presence of lingering stages of the 

 dwindling pinnae. It is usually, but not invariably, complete before the seedlings 

 are able to develoji leaves with two pairs of pinn». Cambage has found it to 

 be the second leaf in A. alata (not counting the members of the opposite first 

 pair of simply pinnate leaves separately), in about a dozen specimens, so that 

 no bipinnate leaves with one pair of pinnae had a chance to develop. He has 

 also found it to be the third leaf sometimes in A. excelsa. In the seedling figured 

 by me (PI. ii., fig. 2) it is the fourth leaf. This is the seedling of the species 

 (prol)ably A. implexa, as Mr. Cambage has been good enough to advise me) 

 which has furnished me with my best and most instructive reversion-shoots and 

 suckers, because the euphyllodcs are so long, up to about 9 inches. I was not 

 interested in the plants before they were scorched, and the portions of the plants 

 above ground killed, but without damage to the root-system, by a bush-fire, or in 

 some cases injured in other ways; and there has not been time yet for the new 

 shoots to flower; and I have been unable to find adult, uninjured plants in a 

 condition suitable for exact identification of the species. In the seedling shown, 

 the first abruptly jjinnate leaf had three pairs of leaflets, but the apical pair, and 

 one of the next i)air below, were missing, when I got the sjiecimen. The second, 

 third, and fourth are bipinnate, with only one pair of pinnae in all of them. 

 One pinna of the second is damaged, and is represented by one leaflet and a 

 portion of its fellow. Above what remains of the damaged pinna in the position 

 shown, the terminal seta at the apex may be seen in the photogTaph of the com- 

 mon petiole, projecting to the left. Tlie fiftli is a short, relatively broad, com- 

 plete euphyllode, 23 inches long; the sixth is longer but narrower; the seventh is 

 still longer; the eighth (bent in the photo) is 7 i inches long. An average 

 sample of a complete euphyllode from a reversion-shoot, 8J inches long, is shown 



