244 



Finally he makes the plunge, and in " Science," N.S., Vol. lxix, January, 1919, 

 p. 91, publishes a letter headed — ■ 



"Eucalyptus Never Present in North America." 



(This begins with an attack on Benthain, quoted in Part LIV, p. 170), and 

 proceeds : — 



'' . . . A few years ago I advanced a theory of origin and distribution for the family Myrtacese 

 which was based largely upon the recent and fossil distribution of the different tribes (Berry. E. W., ' The 

 Origin and Distribution of the Family StyrMcese,' ■/>'"'• Gaz., vol. 59, pp. 484-490, 1915). This theory 

 in its broader outlines considered America as the centre of radiation for the family, and regarded the 

 sub-family Myrtoiderc as the most ancient. The sub-family Leptospermoideas was regarded as derived 

 from the former; and the Australian types, which are the peculiar ones of the family, were regarded as 

 having originated in that region in response to local environmental conditions subsequent to the Cretaceous 

 radiation of the family stock. Genera such as Eugenia and Myrcia were regarded as representing this 

 ancestral stock more nearly than any other of the existing genera. 



'" This theory considered Eucalyptus as one of the more specialised genera, and in this conclusion 

 I agreed entirely with Andrews and other Australian friends, who have repeatedly expressed doubts 

 regarding the presence of Eucalyptus in the fossil floras of the northern hemisphere. Without wishing 

 to be dogmatic about European fossil forms referred to Eucalyptus, and known to me only from figures, 

 I may say that I do not regard the genus as ever having been present in North America, although in 

 conformity with long-established custom and with due consideration for the stratigraphical applications, 

 I have frequently referred fossil forms to this genus. 



''A question of considerable importance is the real botanical affinity of the numerous North American 

 Cretaceous forms which have been referred to Eucalyptus. These arc undoubtedly ancestral to the 

 American Eocene forms referred to Eugenia and Myrcia, and it would probably be not far from the truth 

 if they were referred to the genus Myrcia. I have collected and studied a great many of these Cretaceous 

 types, and some of them are certainly closely allied to, if not identical with, that genus. Others are 

 somewhat remote, and, pending a solution of their botanical affinity, which may never be satisfactorily 

 attained, I would advocate the dropping altogether of the use of Eucalyptus for those North American fossil 

 forms. This usage is seriously misleading from the standpoint of evolution and distribution, and, moreover, 

 is not supported by any valid botanical arguments, as I pointed out in the paper already alluded to at the 

 beginning of this note. The alternative that I suggest is the taking up of the genus Myrtophylhim 

 proposed by Heer in 1869 (Heer, 0., Neue Denks. Schw. Gesell. Naturw. Bd. 23, nem. 2, p. 22, 1869. Type 

 being the widespread mid-Cretaceous species Eucalyptus Geinitzi), and using it for leaves of Myrtacea? 

 whose generic relations cannot be determined with certainty, and more especially for the leaves commonly 

 referred to the genus Eucalyptus." 



Acbowledgmeuls — Mr. W. S. Dan, the well-known Palaeontologist and Librarian, has been most 

 kind in procuring me books from the library of the N.S.W. Geological Survey, and in verifying my 

 references. He could not have been kinder in answering my many letters, but that will not surprise anyone 

 who knows him. I am aNo grateful for a couple of references from Dr. A. B. Walkom. Secretary of the 

 Linnean Society of N.S.W. 1 am not a palseobotanist, and I should have been glad if I could have 

 obtained the help of a \i al or palecobotanical friend to read Parts LIV and LV before publication, 



but that was out of the question, as they grew to be so voluminous. — J.H.M. 



