502 EVOLUTION OF THE EUCALYPTS, 



E. lactea R. T. Baker(Pl. xliv., fig. 5). — Cotyledons as in 

 E paludosa. Leaves opposite, glabrous, entire, subsessile then 

 sessile. 



E. Stuartmna F.v.M.(Pl. xlix., fig.l; PL Ixix., fig. 14).— 

 Cotyledons transversely oblong, obtuse, 0-45 x 015, petiole 0-2 

 cm. Leaves opposite, entire, glabrous, glaucous, ovate, cor- 

 date, obtuse. First pr. 0-9 x 0-3, petiole 015 : second 1-5 x 0-9, 

 third 1-5 X 1-1 cm. Stem terete, glabrous as far as grown. 

 First internode 0-9, second 1, third 1, fourth 1 cm. 



E. melUodora A. Cunn.(Pl. Ivi., fig.l). — Cotyledons trans- 

 versely oblong, obtuse, petiolate, slightly emarginate. Leaves 

 alternate after first pair, glabrous, entire, lanceolate, obtuse 

 then subacute, petiolate. 



E. acervuhi Sieb.(Pl. Ixvi., fig.4). — Cotyledons transverse- 

 ly quadrilateral, obtuse, slightly emarginate, 0-4 x 0-2, petiole 

 0-2 cm., base somewhat cordate. Leaves opposite, entire, glab- 

 rous, lanceolate, obtuse, shortly petiolate for first few pairs, 

 not glaucous. First pr. 11 x 0-5, petiole 0-2; second 1-8 x 0-6, 

 petiole 0-2 cm. Stem terete, glabrous. First internode 0-7, 

 second 0-8 cm. 



This specimen resembles, in the seedling, that of E. palu- 

 dosa, but the cotyledons are smaller, and the leaves narrower. 

 From that of E. Gunnii, it is quite distinct, its primary leaves 

 not being at all like the sessile, ovate, glaucous ones of that 

 species. 



\\.{d). Eucalypts with very small cotyledons, transversely 

 oblong or triangular, with slight or no emargination. 



This group shades off from the previous one, and, in many 

 cases, it is hard to put a species in one or the other. Practi- 

 cally all contain eucalyptol in a greater or less amount, many 

 contain pinene, and others aromadendral and phellandrene. 

 Piperitone is absent. In this class, the cotyledons have been 

 reduced to their smallest dimensions, in contrast to the rela- 

 tively enormous cotyledons of E. calofhylla. The reason for 

 this will be discussed later. 



