ST1.TE HORTICULTURAL SOCIETY. 397 



spring's intense heat. Cold and heat — heat and cold — are but 

 relative terms; their molecular action comes under the same 

 law. If the circulation is uniform throughout, irrespective of 

 the general temperature — for circulation obtains, though feeble, 

 in a frozen plant — there is less danger, doubtless, than when a 

 part is clogged up by a freeze or sudden thaw. 



In his interesting narrative of his "Voyage of Discovery 

 toward the North Pole," Dr. Hayes, after citing to a like testi- 

 mony of Dr. Kane, informs us that when the Greenlauders shoot 

 a deer they immediately eviscerate it; otherwise it will soon 

 putrify, even when the temperature is far below zero. His 

 explanation is this: ''The animal is immediately frozen on the 

 outside, and there being thus formed a layer of non-conducting 

 ice, as well as the pores being closed, the warmth of the stomach 

 is retained long enough for decomposition to take place, and to 

 generate gas, which permeates the tissues, and renders the flesh 

 unfit for food; and this view of the case would seem to be con- 

 firmed by the fact that decomposition occurs more readily in the 

 cold weather of midwinter (in the Arctic regions) thau in the 

 warmer weather of midsummer." His explanation appears 

 tenable, and applies to plants as well. Such phenomena lead 

 us to conclude that any great thermal disparity in the cell 

 layers of a plant produce like results, irrespective of the 

 season; that a gradual freeze or thaw is less dangerous than a 

 sudden one; that when the entire plant is solidly frozen up. with 

 the ground holding its roots, it may be safe; that the transition 

 by heat to circulation is the perilous moment, always perilous if 

 any weakness inheres; that the drought of summer or the dry 

 chill of winter acts by the same law, resulting in injury or ruin. 



Considering all the adverse circumstances and conditions 

 which we have to encounter and try to avert, it is a wonder that 

 in a climate like ours more of our plants do not prematurely 

 "give up the ghost." But experimentation gives us hope. We 

 know that some plants are adapted to almost any temperamental 

 changes. Why, is yet a mystery. We know not how the 

 entanglement of cohesion affects the hardiness of a plant; nor 

 how air or fluid within the circulatory ducts clothes it with re- 

 sisting power against heat and cold. 



A propositional summary of the matter in question is this: 



That a i^lant is safe when competent to respond to the calorific 

 waves in a balanced circulation and development. 



That danger ensues when the waves are too quick and intense 

 for the strength of the plant, as in a "sun stroke." 



