128 THE AMERICAN BOTANIST 



are of course, opposed by the nursery men and florists who see 

 in measures of this kind the threatened extinction of their own 

 business, and the secretary of the Society of American Florists 

 rather disgustedly inquires whether stopping the importation 

 of Japanese lily bulbs will aid in protecting our forests. 



Our most serious plant diseases have always come from 

 abroad for the reason that our plants are not as well adapted 

 to resist these as they are to resist those nearer home. Long 

 ages of warfare with the latter have bred a race of plants that 

 do not easily succumb to their attacks but such plants are often 

 very susceptible to foreign foes. A case of this kind is found 

 in the chestnut blight which got into this country a few years 

 ago, on imported Japanese chestnut stock, and has alreadv 

 killed the chestnut tree over a large part of its range. This 

 disease is still spreading and is now making an occasional 

 assault on allied plants. There is no known way of stopping 

 the disease at present and in consequence all the chestnuts and 

 chinquapins seem to be doomed. Possibly, here and there, 

 more resistant individuals may be encountered and if so, a new 

 race of trees may be produced but only at the expense of much 

 time and money and even then it would be difficult, if not im- 

 possible, to duplicate the magnificent chestnut forests of a few 

 years ago. 



The latest fungus pest to threaten our trees is the white 

 pine blister which has already become firmly established in New 

 England and New York with outposts as far west as Minne- 

 sota. Wherever this fungus gets a foothold, the white pines 

 are rapidly killed. One of the interesting features of this new 

 disease is the fact that the organism which causes it is one of 

 those species that, like the wheat rust, lives upon more than one 

 host in its life cycle. In the case of the wheat rust, spores 

 firmed on the previous year's wheat set up an infection in the 

 leaves of the barberry and from the young plants on the 

 barberry leaves the new wheat is infected. The second host 



