No. 144.J 191 



We observe to-day, on the leaves of the linden trees, just 

 leaved out (generally on each leaf), a single measurer of about 

 one tenth of an inch long, quite active. How wonderful a pro- 

 vision for them, after such an inhospitable spring ! How shall 

 we prevent this? That most beautiful tree is never permitted to 

 pass one summer in peace. 



One rule with regard to our methods of getting rid of the in- 

 sects is the same applied to all evil, moral and physical, " Ohsta 

 principiis''' — " Oppose it in the beginning." We must scotch it in 

 the egg. Let all who think upon this momentous question seek 

 the remedy. 



THE GREAT TREE OF CALIFORNIA. 



The great tree of California has attracted the attention of the 

 American Journal of Science and Art. 



Andrew Williams, of San Francisco, sent to the American 

 nearly three years ago the leaves and wood of it. We have on the 

 table a piece of the wood, including both sap and heart; the 

 heart resembles red cedar in color, and the sap is like pine. We 

 find the concentric rings in both sap and heart to be about an 

 average of 40 per inch, or 4 to 1-1 0th of an inch. 



If the same ratio extends to the centre of the tree then in the 

 semi-diameter of the large tree, at 30 the whole, we have 15 feet, 

 in which are 1800 concentric circles, showing that to be the age 

 of the tree proximately. 



In the Journal, the conclusion attained is an age of 2,066 

 years. 



In the specimens on the table the layers are almost precisely 

 the same in both sap and heart — 80 layers in 2 inches. 



[Dr. Hooker's Flora of New Zealand. From the same Journal.] 



HYBRIDIZATION AND CLIMATE OF PLANTS. 



For seventy years past, at the garden at Kew, England, up- 

 wards of twenty thousand plants grow in open air, plants from 

 all quarters of the globe, and this within a space which, if left 

 to nature, would not have contained 200 indigenous plants. 



