BY E. C. ANDREWS. 



535 



Acknowledgments. — The Writer desires to record here his in- 

 debtedness to Messrs. R. H. Cambage, J. H. Maiden, R. T. Baker, 

 H. G. Smith, and C. Hedley, in the preparation of the present 

 paper. During joint excursions made in Eastern Australia, the 

 Writer learned, from Mr. Cambage, the names of the plants, their 

 habitat, and the soils in which they flourished. Throughout the 

 preparation also of the note, Mr. Cambage has given kindly advice 

 and criticism, especially with regard to points pertaining to field- 

 botany. 



To Mr. Maiden, very cordial thanks are tendered for access at 

 all times to the storehouse of literature and plants at the National 

 Herbarium, attached to the Sydney Botanical Gardens; also for 

 access to the very numerous unpublished drawings of Eucalypt 

 anthers which he has prepared, and for his great personal kind- 

 ness in answering any queries as to general botanical information 

 bearing on the point under consideration. To Mr. E. Cheel and Mr, 

 A. A. Hamilton also, the Writer desires to return sincere thanks 

 for their kindness in facilitating research in the National Her- 

 barium. 



To Messrs. Baker and Smith, the Writer is deeply indebted for 

 the new light which their "Research on the Eucalypts" has thrown 

 upon the problem of Eucalypt-distribution and classification 

 especially in connection with the relations existing between oil- 

 contents and leaf-venation. 



To Mr. Hedley, the Writer is deeply indebted for personal com- 

 munications concerning the general principles of plant- and ani- 

 mal-distribution in the Southern Hemisphere. 



Thesis. — The family Myrtacese originated in the fertile tropics, 

 and had a much wider range in the late Mesozoic than at present, 

 owing to the large epicontinental seas, the low-lying lands, and 

 the mild and moist climate of the Cretaceous. With the great 

 increase in size of the continents during Post-Cretaceous time, and 

 the formation of high and broad mountain-borders to the conti- 

 nents, the genial climate of the Cretaceous became differentiated 

 gradually into distinct zones, and the northern and southern range 



