492 



FURTHER NOTES ON HYBRIDISATION IN THE 

 GENUS EUCALYPTUS. 



By J. H. Maiden, Government Botanist, and Director of the 

 Botanic Gardens, Sydney. 



Towards the end of 1903 I sent a paper* to the Australian 

 Association for the Advancement of Science, which, through 

 unavoidable causes was issued only in June, 1905. It was 

 intended as a manifesto formally announcing my belief in hybri- 

 disation in the genus. Since that paper was written, and before 

 it was published, I have taken various opportunities! of drawing 

 attention to the subject, and the object of the present paper is to 

 bring additional evidence before this Society. 



I take the opportunity of emphasising the fact (related in 

 detail under E. Boormani, infra) that the original discoverer of 

 hybridisation in the genus was G, Caley, and he made his 

 observation before 1810. 



I also take the opportunity of recording that Mr. Walter Gill, 

 Conservator of Forests, Adelaide, has informed me that he has 

 held the opinion for over twenty years that Eucalypts hybridise. 



How is a natural hybrid to be determined 1 I believe the 

 following are guides : — 



1. A natural hybrid is usually found in the neighbourhood of 

 its reputed parents, and is always sparsely distributed. 



2. In many cases the reputed hybrid, practically identical in 

 character, is found in localities widely separated. 



* " On Hybridisation in the Genus Eucalyptus,'^ Report Vol.x. (Dunedin 

 Meeting, January, 1904). The paper contains several bibliographical 

 references. 



i E.g., 'Critical Revision of the Genus Eucalyptus,' v. 140; vi. 164: 

 ' Forest Flora of New South Wales ' : papers in these Proceedings. See also 

 Victorian Naturalist, xxi. 114, 116. 



