ACCLIMATING PLANTS. 75 



Doubtless, artificial heat, skilfully applied, as it is in the raising 

 of plants under glass, may take the place of the less refrangible 

 heat rays, to some extent, but not enough to prevent the plants 

 from showing their appreciation of the increasing influence of the 

 sun, as he starts on his northward journey about the last of 

 December. The rigor of all northern climates prevent unprotected 

 plants from showing their appreciation of this gradually increasing 

 influence of the sun, till the amount of it has become sufficient to 

 prevent hard freezing at night, and just in proportion as they have 

 been prevented from yielding to that influence is their activitj'^ 

 great ; so by late planting, greater activity in early life is obtained, 

 and the maturing elfect of the gradual withdrawing of the sun's 

 heat influence, and the increasing power of the violet raj'S bring 

 the plant sooner to maturity, thus shortening its period of growth, 

 and rendering its seed capable of coming earlier into activity, in 

 the spring. If, to the sun's influence, there should be super- 

 added that of the fall frost, checking maturation, and holding the 

 food elements of the embryo where they are best fitted to be taken 

 up in the spring, then we have seeds which will germinate still 

 earlier, and thus will be longer under the accelerating influence of 

 the increasing heat and light ra3^s of the sun, and so, will show bet- 

 ter development than their progenitors, and as short a jieriod. 



Discussion. 



Marshall P. Wilder asked whether Dr. Waters' improved varie- 

 ties were produced wholly by planting, or whether the scientific 

 principles referred to were taken into consideration. 



Dr. Waters did not think that acclima,tion could be accomplished 

 with a single plant, but believed that it could be with a series, by 

 repeated sowings of seed. 



Charles M. Hovey said that herhad been much interested in Dr. 

 Waters' recapitulation of facts, but did not see their application to 

 the acclimation of plants. There is much to be said on that point, 

 but the improvement of plants is quite another thing. A society 

 for the acclimation of animals and plants existed in Paris for many 

 3'ears, but still acclimation is a thing which has never been 

 accomplished. The English climate is not warm enough to ripen 

 Indian corn, tomatoes, squashes, melons, or cucumbers in the 

 open air, under ordinary conditions. Mrs. Marryatt's gardener 

 informed Mr. Hovey many years ago that he attempted the culti. 



