6 4 



EUCALYPTUS GLOBULUS. 



The spiral vessels are the connecting links between the air of 

 the outside world and the roots of the tree. In making the 

 cross section of the leaf some of the spiral vessels were cut 

 across and can be seen at C figure 2. When the atmosphere 

 around the tree is very dry you will find these stomates closed 

 tightly so as to retain all the possible amount of moisture 

 within the plant ; but if the air is very moist these stomates 

 will be wide open, to admit of a free circulation. A remark- 

 able characteristic of the eucalyptus leaf is the presence of 

 nearly the same number of stomates on the upper surface of 

 the leaf, as upon the lower, something uncommon except in 

 water plants. 



The eucalyptus tree has a remarkable reputation just at 

 present, for absorbing malaria or miasma from the surrounding 



Fig. 4. Stomates from the Upper Surface of the Leaf. 

 Drawn with the Camera Lucida. 



atmosphere. So large tracts of land in the Campagna di Ro- 

 ma have been devoted to raising a forest of eucalyptus trees. 

 Some advanced botanist has suggested this virtue of the tree 

 was due to the great number of stomates on the leaves, and it 

 seems a safe theory to adopt. 



Through southern California the eucalyptus trees are being 

 systematically cultivated for fuel. Two hundred and twenty-five 

 trees are generally planted to the acre and it is estimated that 



