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TRANSACTIONS OF NORTHERN ILL. HORTICULTURAL SOCIETY. 277 



If a farmer should let his cattle, horses, sheej), etc., go into a night 

 of minus 40° temperature, in a half starved condition, he need not feel 

 surprised if, in the morning, some of them foil to live. And if you or I 

 ha])pen to be underfed and weakened by abstinence from food, or 

 deranged in our physical functions by the use of indigestible food, we 

 should be poor subjects for exposure to arctic cold, or to violent changes 

 of temperature in cither direction. 



I believe that starvation weakens all vitality, and plants and animals 

 stand together in subjection to this proposition. Hence, if a plant goes 

 into winter in a starved condition, it must give up and die with a harrl- 

 ship which would be little felt by it if it had been in a full-fed, perfect, 

 physiological condition. 



But the animal is a constant feeder, (except, of course, the hiberna- 

 ting animals,) and his digestion, assimilation and supply of waste, is a 

 constant quantity, while the plant must not only do in summer all that is 

 requisite for its ])rosperity during the current season, but must also do at 

 that time all that is necessary to fit it for hibernation, and also for its 

 assumption of growtii in the spring. From the time that the leaf falls in 

 autumn till it is reproduced in spring there is a restricted, but still con- 

 stant evaporation of moisture from all parts of a tree above ground, 

 except when the air is in a condition of saturation. Whence comes the 

 moisture to supply that evaporation, and still leave enough behind to 

 keep the cells and vessels well filled ? Suppose the roots are every one of 

 them encased in solid, frozen ground, which must be the case with many 

 young trees in our climate, at least in some seasons. There must be some 

 provision of supply within the tree. There must be some chemical re- 

 action brought about by the winter cold which forms liquid from the solid 

 matter already in the tree. The behavior of the maple and other saj)- 

 flowing trees supports this surmise, and upon no other hyj)othesis can I 

 explain the facts evident in tree hibernation. The maple, if tapped be- 

 fore freezing weather in autumn, will be found comparatively dry of sap, 

 while experiment has showMi that a root may be cut ol'f at each end in 

 spring, and when the temperature is right will flow copiously from each 

 end. Then if the temperature is lowered it will cease flowing, and when 

 the temperature is again raised the flow will begin again and continue till 

 exhausted. This supply of UKjisture for evaporative purposes, in case 

 severe freezing cuts off the supply from the earth, must be i)rovided for 

 then by the storing away of some solid from whicli the water can be pro- 

 duced ; some solid, which either holds as constituent parts of its substance 

 hydrogen and oxygen, which it can spare when the low temperature 

 releases them, or some solids which, by mutual reaction under the influ- 

 ence of low temperature, give rise to new bodies, of which water is one. 

 But there is a far greater want to be i)rovided for by every hibernating 

 plant before it reaches winter, and that is the food ui)on which growth is 

 to be started in spring. 



An effort of wonderful power must be made by the tree w henever it 

 is warm enough in soil and air in sjjring. It must increase the already 

 formed parts of every bud to many hundred times their original size, and 



