128 The Ottawa Naturalist. [September 



of 1896. That winter it killed to the ground and only made weak 

 growth in 1897 ; the next winter it killed back Yz, the third y^ ; 

 the fourth winter it was almost hardy to the tips, and it was also 

 the same last winter. This is a good example of the acclimatiza- 

 tion of trees, 



Cornus Jlorida, Linn. (Flowering Dogwood). One specimen 

 of this tree was practically hardy from 1897 until last winter, when 

 it killed to near the grouna. Other specimens were not as hardy. 



Nyssa sylvatica, Marsh (Sour Gum). The tree now living 

 was planted in the spring of 1897 ; the first winter it killed back 

 ^, the next ^, the third it was hardy nearly to the tips, and 

 again the same last winter. 



Sassafras officinale, Nees. (Sassafras). This has killed out 

 root and branch thus far, though it has not been as thoroughly 

 tested as some of the others. 



The following other trees peculiar to south-western Ontario, 

 appear to be hardier than the above, and some individual trees are 

 perfectly hardy. 



Platanus occidentalism Linn (Button wood). 



Castanea sativa, Mill, var. Americana (Chestnut). 



Fraxinus quadrangulata, Michx. (Blue Ash). 



Gleditschia triacanthos, Linn. (Honey Locust). 



Some of the rest, such as Gymnocladus canadensis, Cratcegus 

 Cms galh, Pyrus coronaria, -And Juglans tiigra, are quite hardy. 



A few of the coast trees of British Columbia kill out root 

 and branch, among such being Acer macrophyllum, Arbutus 

 Menziesii, Cornus Nuttallii and Quercus garrayana. 



It is interesting to note that, out of the list of 121 species of 

 native trees published by Prof. J. Macoun, about 100 have proven 

 hardy or half hardy here, and the writer has no doubt that, when 

 all the species are tested, there will not be more than 10 which 

 can not be grown at Ottawa. 



The question of the acclimatization of trees, shrubs and plants 

 is a very important one, and one in which there is a good field for 

 work at the Central Experimental Farm. I have mentioned a 

 few instances where native trees have gradually become hardier 

 after being planted several years. It might have been further 



