282 



B. The younger leaves opposite, the adult ones alternate. This sections consists 

 of five species, as follows : — 



E. hyper icifolia Dumont. E. hirsuta Link 



E. purpurascens Link E. pulverulenta Link. 



(amygdalina Labill.) E. cordata Loddiges. 



2. A. P. de Candolle, 1828. — De Candolle, [in his Prodromus, Part III, p. 210, 

 combines the use of the operculum and calyx-tube with the position of the leaf for 

 purposes of classification. His sections are : — 



(1) Altemifolice. — Alternate leaved, with leaves undoubtedly all alternate. 



(2) Oppositifolke. — Opposite leaved, the leaves in some opposite and sessile (these 



are juvenile leaves J.H.M.), the others alternate and petiolate. 



Section (1) he subdivides according to the relative length and size of the 

 operculum and calyx-tube (cupula.) Although he gets his idea from Link, his illustra- 

 tions of species are, on the whole, different. 



An English translation of de Candolle, in detail, will be found in George Don's 

 " Gen. Hist. Dichlamydeous Plants," ii, 818 (1832). 



3. Beutham, 1866. — Bentham (B.F1. iii) in 1866, gave but few references, as. he 

 realised it was a subject that could only be adequately dealt with in Australia; at all 

 events the material available to him at that time was insufficient. He says : — 



Leaves in the young saplings of many species, and perhaps all in some species, horizontal, 

 opposite, sessile and cordate. (B.F1. iii, p. 185). 



Then he goes on to say : — 



The extraordinary differences in the foliage of many species at different periods of their growth 

 add- much to the ordinary difficulties arising from the gradual transition of varieties, races, or species one 

 into the other; moreover, a considerable portion of our herbarium specimens have been gathered to 

 illustrate collections of woods by persons little' acquainted with botan}'. and are but too frequently not 

 in a state to supply the most essential characters, The old division of the genus according to the opposite 

 or alternate leaves is now found to be quite fallacious, so many species having them opposite at an early 

 stage, and alternate when full grown, (p. 186). .... 



A great majority of the species are now known to have on the young sapling, or even on 

 adventitious barren branches of older trees, opposite sessile broad or cordate leaves, passing gradually 

 into the ordinary alternate petiolate narrower ones. It appeared quite useless in any manner to describe 

 these sapling leaves in the several species where they have been observed, for they present at once 

 similarity in the corresponding leaves of different species, and the greatest dissimilarity in the different 

 leaves of the same species or specimen. Where in the following pages the leaves are described as opposite or 

 sessile, it is meant that they retain that form on the flowering branches . . . Diagnostic characters are ' 

 sometimes taken from the position of the leaves, horizontal or vertical (p. 187). 



4. Mueller, 1869. — In Fragm. vii, 44 (1869), at the end of the descriptions of a 

 large number of Eucalyptus seedlings, Mueller adds : — 



The descrijitions of Eucalyptus seedlings raiseel in a garden are easily confused with those of 

 shoots of the parent tree, concerning which there may be difficulty in attributing them to their botanical 

 origin. 



This is the first published statement, to my knowledge, of the similarity of 

 seedling to the corresponding sucker leaves (usually termed by me " juvenile leaves"). 



