.BY A. A. HAMILTON. 177 



1-eference to venation. In a paper published in the Botanical 

 Gazette, University of Chicago Press (Vol.59, 1915, p. 484) on 

 "Tiie Origin and Distribution of the Faniilv Mvrtacese," Mr. 

 Edward M. Berry, referring to a paper on tliis subject by Mr. E. 

 C Andrews, published in these Pi-oceedings (1913, p. 529), says 

 (p. 486), "for althougli in accordance with paleo-botanical usage 

 I have identified numerous forms of Eucalyptus in the N. 

 American Upper Cretaceous, I have long thought that these 

 leaves represented ancestial forms of Eugenia or Myrica. but 

 have hesitated suggesting any change based merely on personal 

 opinion, and also from a consideration that such change in 

 nomenclature is undesirable at the present time from the stand- 

 point of stratigraphic paleobotany." Mr. J. H. Maiden(17; pl"7) 

 says : — " Except in the case of very characterrstic material 

 botanists who deal with the existing flora usually ask to be 

 excused from determining a plant on a leaf only." In (20c, 

 p. 326), the author says: — "Other characters of Eucalyptus 

 leaves we require to know more about, are their size, texture, 

 and prominence of venation. They ai-e minor characters, and 

 some species present much variation in this respect": and in (18; 

 Part viii., p. 247) Mr. Maiden says: — " I attach great importance 



to studying the trees in the field In these researches I maj' 



be pardoned for saying that I have travelled moi'e or less in 

 every State of the Commonwealth, covering thousands of miles 

 on foot in pursuit of this study alone, in contradistinction to 

 mere herbarium work." Mr. E. C. Andrews(l), discussing "The 

 Age of Dicotyledons," gives (p. 360) examples of the difficulty of 

 determining the correct botanical classification of existing plants 

 on leaf -characters, showing differences of opinion among our 

 greatest .systematists, as to the family in which certain trifoliate- 

 leaved plants should be placed. Sir J. I). Hooker (14; p. 13), 

 says:— "The result of my observations is that differences of 

 habit, colour, hairiness, and outline of leaves .... are generally 

 fallacious as specific marks, being attributable to external causes 

 and easily obliterated under cultivation." 



Specimens of the examples cited in this paper will be incor- 

 porated in the National Herbarium. 



14 



