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DOMESTIC BOTANY. 



Gum Trees. Few families surpass this in large timber 

 trees, especially as represented by species of the genus Euca- 

 lyptus. Their native coimtries are Australia and Tasmania, 

 where they form large forests. There are not less than from 

 100 to 150 species described, but they vary so extremely, in 

 different kinds of leaves being produced on various branches 

 of the same tree, thus presenting distinct specific characters, 

 and in the varying nature of their bark, that the deter- 

 mination of species is very difficult. In Tasmania they 

 are described as rising to the height of from 200 to 400 feet, 

 with a diameter of from 6 to 8 feet. Their naked gaunt 

 stems, of 100 or 150 feet clear of branches, present the ap- 

 pearance of a forest of artificial columns. These, sometimes 

 blackened by the fires of the natives, and with the shaggy 

 loose bark hanging about them, afford a grand but dismal 

 spectacle. Trees of equal, if not larger size, are found in 

 Victoria, a fallen one measuring 480 feet in length, while one 

 still larger measured 80 feet in circumference. 



According to the nature of their bark, they receive various 

 names, such as Stringy bark (^E. gigantea\ Iron bark {E. 

 persicifolia), Blue gum {E. globulus)^ Peppermint tree (^E. 

 amygdalind) ; some also receive the name of native mahogany, 

 which, -with the kind called Grey Iron bark, &c., are im- 

 ported to this country. The wood of some is very hard and 

 durable, and so heavy as even to sink in water. Many yield 

 gum E. resinifera^ a gum kino, and E. amygdalina, an oil 

 which comes to this country in considerable quantity. E. 

 mannifera and others yield sweet secretions analogous to 

 " Manna." It is also stated that E. Gnnnii furnishes a great 

 quantity of liquid that ferments and forms a kind of beer. 

 They produce abundance of seeds which vegetate freely, and 

 have, through the agency of man, become naturalized in 

 many countries. As they are of robust growth, a " struggle 

 for life" in the natural vegetation is the consequence. Many 

 years ago large quantities were raised at Kew, and experi- 

 ments tried with them in the open air ; they grew vigorously, 

 and several species withstood ordinary winters, but the severe 



