473 



THE EVOLUTION OF THE EUCALYPTS IN RELA- 

 TION TO THE COTYLEDONS AND SEEDLINGS. 



By Cuthbert Hall, M.D., Ch.M. 



(Plates xxxviii.-lxix.) 



Introductory. — Although so much work has been done in 

 elucidating the botanical, chemical, industrial, and other rela- 

 tions of the various species of Eucalyptus, the subject of the seed- 

 lings, and especially of the form of the cotyledon-leaves, and the 

 part the latter have taken in the evolution of the genus, has 

 received scant attention. Our two main contributions, so far, 

 have been from Lubbock, in his "On Seedlings," in which the 

 seedlings of ten species are described; and from Baron von 

 Mueller, in his " Eucalyptographia," in which he gives drawings 

 of the cotyledons of twenty species; but some of these are far 

 from accurate, especially in the case of E. amygdalina and E. 

 globulus. In this research, I have investigated the seedlings of 

 nearly 150 species, and so have been able to compare one with 

 another, and to trace the development of the higher from the 

 more primitive forms, and gain an idea of the influences which 

 brought this about. 



I am under a deep debt of obligation to Mr. R. T. Baker, 

 F.L.S., for supplying seeds that were botanically correct, and for 

 identifying the species where seeds were collected by myself; to 

 Mr. H. G. Smith, F.C.S., for help and advice, and to Mr. T. C. 

 Roughley, of the Technological Museum, Sydney, for the ex- 

 cellent series of photographs of the mounted seedlings taken by 

 him. The seeds of most of the Western Australian species were 

 obtained from Mr. J. Staer, and so I have to rely on his naming 

 of them. Those from him were E. calojihylla, E. cornuta, E. 

 diversicolor, E. eudesmioides, E. gomphocephala, E. leptopoda, E. 

 Lehmanni, E. loxophleba, E. mm-ginata, E. occidentalis, E. per- 

 foliata, E. platyj)hylla, E. jjolyanthema, E. redunca, E, mlubris^ 



