THE PLUM 323 



assumed that the plants of temperate zones had 

 taken on the habit of winter rest merely because 

 this habit was forced upon them by the exigen- 

 cies of climate. And indeed, there is no reason 

 to doubt that such was really the origin of the 

 habit of winter rest. We have had at least one 

 illustration, in the case of the winter rhubarb, 

 of the readiness with which a plant resumes the 

 habit of perennial activity. 



We suggested in that connection that peren- 

 nial growth is the normal and primitive habit of 

 the plant ; and there can be no occasion to modify 

 that suggestion. 



But even though the winter sleep of the plant 

 was forced upon it, there is reason to believe that 

 the habit thus inculcated is of great utility in 

 conserving the energies of the plant and promot- 

 ing its vital efficiency. 



The experiments that justify this conclusion 

 have been made in recent years by a number of 

 different botanists, and they have conclusively 

 demonstrated that it is quite the rule for a plant 

 to develop exceptional powers of growth imme- 

 diately after it comes out of a period of dormancy 

 induced artificially. 



Plants narcotized with the fumes of ether or 

 chloroform, for example, are rendered quite in- 

 capable of growth while subjected to the fumes. 



