160 THE INFLUENCE OF COLD ON ANIMAL LIFE. 
locomotion to those who have from the beginning the power of 
maintaining their temperature against moderate cold. The young 
of none of our domesticated animals have, at first, the power of 
maintaining their temperature against severe cold. The farmer 
knows this to his cost, when, after a severe night’s frost, he finds 
so many dead lambs. If he has neither the foresight nor the 
humanity to afford them the little shelter which they want (for 
‘‘ they are born with their eyes open,” and have the power of 
maintaining their temperature to a very considerable degree, so 
that a few hurdles with straw, or a warm quick hedge to break the 
cutting blast, would save the greater part of them), he is rightly 
served. 
We talk of these newly-dropped lambs being starved with 
cold, and dying palsied but the truth of the matter is, that they 
so rapidly cool^ down from the inability to produce heat, that 
they become enfeebled, and motionless, and insensible, and life is 
literally extinguished. They soon, however, acquire this power 
of producing heat; for if they die after tw'O or three days have 
elapsed, it is from other causes than the diminution of tempera¬ 
ture. 
The cause of death being known, the means of resuscitation are 
also developed. The shepherd knows well, that many a lamb, 
that is quite motionless, and to all appearance dead, may be 
revived, if "he is put before the fire, or covered with warm flan¬ 
nel ; but he know^s also, that although life may be restored, the 
extreme debility produced by the cold is not always or soon 
removed ;—that this is for a long while a weakly lamb, and will 
sink under many a disease that his companion will weather. 
Sometimes the recovery will be but temporary, and they will 
rapidly dwindle away and die. 
Dr. Edwards points out another relation between the power of 
producing and supporting the reduction of heat—they are in an 
inverse ratio to each other. Dr. Edwards’s physiological rea¬ 
soning on this will be read with no inconsiderable interest. 
“ Whatever degree of care parents may take of their young, 
they cannot always remain with them in order to maintain their 
temperature at a high degree, if they are of that class of ani¬ 
mals which are born with eyes closed, and without feathers. 
As soon as they leave them to provide subsistence, the tempera¬ 
ture of their young begins to be reduced j and if this reduction 
were as injurious as it is to those animals which produce more 
heat, the greater part would perish. Other young warm-blooded 
animals are not exposed to similar reductions of temperature, 
because they are born with a more abundant source of heat. 
But if the external temperature were such that it lowered that 
