52 Popular Errors respecting Trees. 



their time, — that is, before they have undergone their period 

 of rest, which is from tAvo to four months, according to treat- 

 ment. In the month of March, with the temperature at 40"^ 

 at night, they will break rapidly ; while a continued temper- 

 ature of 50 to 60° at night, all the month of December, will 

 have no perceptible effect whatever. 



Such cases we think sufficient to show that there is not 

 the least danger of the swelling of the ripened buds of trees 

 or*plants, by even the warmest weather which we are ever 

 likely to have in the early part of winter. The sap has, at 

 that season, undergone the change which prepares it for 

 winter, and it can be excited to action only by an extra- 

 ordinary amount of heat and moisture. The effect of simi- 

 lar weather in March, however, is quite another thing ; then 

 there is no doubt of the injury which might be produced. 

 The natural season of vegetation is then approaching, and a 

 slight augmentation of heat immediately increases the ac- 

 tivity of the sap. 



We were just on the point of preparing this paper when 

 our last foreign journals came to hand. Almost the first 

 article we noticed was an abstract of a communication by 

 Professor Heer, of Zurich, on the Vegetation of Madeira, 

 translated from a Geneva paper. It completely and fully 

 sustains all we have written, and shows conclusively that 

 there is not the slightest foundation for the popular error that 

 the warm weather of winter will excite vegetation. We 

 copy the article entire : — 



M. Heer, of Zurich, so well known by his observations on 

 the botanical geography of the Swiss mountains, having been 

 compelled by the state of his health to make some stay at 

 Madeira, has employed his time whilst there in studying, in 

 various points of view, the vegetation of that island, — the 

 climate of which is remarkably equable throughout the year. 



Since his return, he has laid before the Societe Helvetique 

 des Sciences Naturelles several interesting observations rela- 

 tive to the periodical phenomena of vegetation. After re- 

 marking that all the woody plants of Madeira are evergreen 



