REAL FACTORS IN ACCLIMATIZATION. 41 



phrase. I said a man with a full stomach can stand a good blast of wind 

 in cold weather, whereas a person with an empty stomach cannot stand 

 so much. I have found that out with plants. For instance, we take 

 evergreens, planting them in vases in the fall of the year, taking up all 

 the roots, and putting them into those tubs or vases, or places where 

 they have not been growing, just for decorative purposes — I find that as 

 long as the moisture is available, they stand all right. But as soon as 

 it freezes up, and dry-cold wind comes, then the plant suffers and it 

 sort of curls and folds up and it generally gets its death-blow during such 

 a period, when we have the very extreme cold, and no water is available. 

 I find that where they are exposed and where they can get the moisture, 

 they can stand so much more cold, than where they are more dry, and I 

 think that is very correct. 



The President — I was struck, in listening to this paper, with the 

 sweeping statement concerning moisture. I expected to see some proof 

 of this statement, but he does not offer anj'. It is simply an assertion. 

 What we want is the proof. Now, in regard to this question of moisture, 

 if you look at the condition of various plants in their natural habitat, you 

 will notice in the district north of this city where we have very rocky 

 hills and our forests are very rocky, that you find trees growing in 

 situations where they are as nearly destitute of water as they would be 

 in any desert in Arizona, except the moisture of the air. There seems 

 to be no soil moisture. I have given special attention to this matter of 

 the growth of forest trees where the situation would seem to indicate, 

 ii not absolutely prove, an absence of soil moisture that would be ac- 

 counted fatal to almost anything. Perhaps we may say that these roots 

 penetrate to the crevices of the rocks to great depth. Indeed, they do 

 undoubtedly, but owing to the situation, the supply of soil moisture is 

 extremely limited, but still they will stand the droughts of summer and 

 the freezing of winter and come through with marvelous hardiness. Of 

 course, they have the same degree of air moisture as other trees. In fact, 

 whoever is familiar with the forest region of our country notices that 

 this rather conflicts witli his assertion. 



Dr. Hansen — Just an observation which ought to go on the record, 

 possibly, in this connection : We find it a common practice in the north- 

 west where we have 40 degrees below Fahrenheit, sometimes without any 

 snow, that it is a great advantage not to permit apple trees or other fruit 

 trees or plants to go into winter quarters without an abundance of 

 moisture in the soil, to give the plants or trees a thorough watering just 

 before they freeze up, otherwise they are very much more injured. 



The President — There is a common expression all through the 

 United States, to the effect that it is very disastrous when the winter 

 sets in before the swamps are full of water. When the swamps are full 

 of water, then let winter come, but before the swamps are full, it is 

 disastrous, and occasionally, we will have a season that is so dry that the 

 swamps are not full of water, and then we see in the plantings of our 



