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It is a well-known and generally conceded principle in science, that ** Life in nature 

 is adapted to its environment," — a comprehensive expression which implies a great deal. 

 It generally implies that long continued association has brought the life and 

 the conditions into perfect harmony ; wbich may imply that it has unfitted that life for a 

 different condition. How little of the life of the temperate zones can endure the condi- 

 tions of either the arctic or the tropic zones, so that what would be true of tlio life in one 

 would not be true if tried in the other. In considering this subject, then, we must take 

 into account the conditions to which the life we arc dealing with has become adapted ; it 

 would never do to subject the life of temperate latitudes to the conditions of the Arctic 

 regions, and draw our conclusions from the result. 



If any form of life, from whatever cause, changes its locality, it must accommodate 

 itself to its new conditions or perish. "There are a few forms of life that can withstand 

 the extremes of heat and cold, but there are for every form average conditions, geologic 

 and climatic, wliich are most favorable for its attaining to its fullest development." We 

 know that some forms of life can accommoilate themselves to altered conditions with 

 comparative ease, some, with great difficulty, and some, not at all If they succeed, they 

 may have to undergo considerable change in life, form, colour or habit, to bring them into 

 harmony with their new environment, hence what we have to discover specially, is the 

 powers of resistance to frost that are possessed by the insects of our latitude. 



It will enable us to attain to a clearer comprehension of the subject, if we keep 

 before the mind, the distinction that exists between warm and cold blooded animals. 

 The one by their internal heat and external covering, can maintain an almost uniform 

 temperature regardless of the state of the surrounding atmosphere, whilst the otiier has 

 seldom any external covering, has little internal heat, and parts with that little readily 

 whenever the external temperature goes lower. 



It has been stated as a general principle in physiology, that, " wherever there is life 

 there is heat." This may be true of active life, but there is such a thing as inactive life. 

 For instance a tree may be frozen to the core and yet not be dead ; there is no manifesta- 

 tion of life, but that is simply the result of unfavorable conditions. A more correct 

 principle, and one I believe of universal application, is " that wherever there is respir- 

 ation there is heat." For example, active vegetation respires ; and the vegetative process 

 is known to be productive of heat in some measure. The chemical combination by which 

 heat is produced and maintained in warm-blooded animals, is, in great measure, well 

 known and easily understood. Heat is the result of combustion. Combustion is obtained 

 by a commingling of oxygen with carbon. The food taken into the stomach supplies the 

 carbon, the air breathed into the lungs provides the oxygen, the blood flowing through 

 the lungs is exposed over a superficial surface ot from a hundred to a hundred and fifty 

 square feet, it is thereby oxygenized, then carried in the veins to the remotest parts of 

 the organism, and when liberated unites with the carbon of the tissues ; combustion 

 ensues, and calorification is the result. Wherever there is combustion there is waste, so 

 waste matter is thrown oil, and its place taken by fresh material. Then again, activity 

 produces heat. Physical exertion produces rapid respiration and circulation, which pro- 

 duces more rapid combustion; consequently more heat. But most animals have a regulat- 

 ing apparatus of some kind for equalizing their temperature ; when this heat is excessive, 

 the pores open and evaporation produces refrigeration ; when cold comes, these 3lose and 

 their heat is economized. With those of them that hibernate, the same principles are in 

 operation. During summer time they have been laying in a supply of carbon in the 

 shape of fat ; on the approach of winter they retire to their hibernacula, settle themselves 

 down and become somnolent. Being inactive, respiration is reduced to the minimum, 

 consequently combustion is slow, and their heat is correspondingly reduced, but they are 

 always warm, if alive, and they invariably leave their winter quarters greatly reduced in 

 flesh. Now mark the contrast with cold-blooded animals, to which insects belong. They 

 have but little heat to begin with, some requiring the most delicate instruments to detect 

 the existence of any. Not being endowed with any regulating apparatus to save it, they 

 part readily with what little they have as soon as the surrounding temperature goes 

 lower, activity with them does not maintain heat, their activity depending entirely upon 



