279 



grew extremely closely. Their height was from 40 to 50 feet. Some were half a foot in diameter, while 

 others were extremely slender. Thousands of Manuka (Leptosperrhim scoparium) seedlings sprang up along 

 with those of the Gum ; and it must not be forgotten that Manuka, far more than most of the indigenous 

 plants, can reproduce itself again and again after burning, and can exclude almost all other vegetation. 

 But in this case the great rapidity of growth gave the Gums the victory, and eight years ago only a little 

 Manuka remained near the margin of this remarkable and quite natural forest growth. 



But this is only one phase of dominance. We want observations, as quantitative 

 as possible, showing the way in which various species attain large size and crowd out 

 or smother other species. The Taxonomic portion of this work now enables foresters 

 to recognise the Eucalypts. These remarks should be read in connection with Coppicing, 

 in Part XLVIII, p. 249, where another phase of Dominance is incidentally referred to. 



In the photograph, to be reproduced later, supplied by Mr. C. J. Weston, Affores- 

 tation Officer of the Federal Territory, we have a lesson taught, as regards a few species, 

 in a limited area, and it shows how E. Macarthuri has dominated certain species. 



But what we mainly want are observations in regard to what may be termed 

 the natural dominance of the trees of the forest, in order that this factor may be taken 

 cognizance of in the plans for commercially working the forest. 



H. — Natural Grafts. 



1. Cohesion of Branches. 



See an Appendix entitled '*' On some Natural Grafts between Indigenous Trees," 

 to my " Forest Flora of New South Wales," vol. vi, pp. 79 and 287. This is based on 

 an earlier paper by me in Joiirn. Roy. Soc. N.S.W., xxxviii, 36, (1904). Most of the 

 references are to adhesion, not cohesion. I give some cases of true cohesion — that is 

 to say, the branches of only one species being concerned. 



See also a fine example of a natural graft in E. tereticornis on the original 

 Bathurst, New South Wales, road, between Sidmouth Valley and Rainville Creek. 

 The photograph (April, 1909) is by R. H. Cambage, and is reproduced in my " Forest 

 Flora of New South Wales," vol. vi., p. 287. 



In Vict. Nat., xxvii, 207 (1911) is a note by Mr. J. W. Audas, with an excellent 

 photograph of cohesion of branches in E. elceophora F.v.M., locally known as " Grey 

 Gum." It is near the Beaconsfield State School, Victoria, and was pointed out by Mr. 

 McCann. The tree is about 15 feet in circumference at the base, and attains a height of 

 about 50 feet. It forks about 10 feet from the ground, and unites again at about 25 feet. 

 After this union four large limbs spread out. The junction is quite 3 feet by 3, and the 

 limbs growing thereon are much thicker than those below the union. 



In Vict. Nat., xxxviii, 13, June, 1921, there is a statement by Mr. Audas that 

 he has seen in the Balangum Ranges, Grampians, Victoria, a Yellow Box (E. melliodora) 

 and a Grey Box (E. hemiphloia var. microcarpa), which have different root-systems. 

 The usual circumstance is that the trunks fuse only a few feet from the ground, andj 



