78 PART II. SOME IMPORTANT METHODOLOGICAL TERMS. 



it evident that nothing is gained and everything is hazarded by 

 obstinately clinging to a superstition wofully at war with reality. 

 The further science advances, the more patent it will become 

 that it is capital folly to ground a generalisation on aught but 

 exhaustively studied data. 



The leading facts of nature are complex beyond anything anticipated 

 by those who extol to the heavens the deductive method. Take, for 

 example, the effect of the radiant heat of the sun on the different sur- 

 faces whereon it strikes. "The greatest contrasts are found between land 

 and water surfaces. If the solar radiation fall on a water surface, the 

 absorption in the uppermost layers of the water is not nearly so complete 

 as is the case with a land surface. The water is transparent to some of 

 the radiation which therefore passes through it to be gradually absorbed 

 by the lower layers. The heat is thus more widely distributed, and the 

 rise of temperature in the surface layers is proportionately reduced. Still 

 more important is the fact that water has a much greater so-called specific 

 heat than soil or rock that is to say, a much greater amount of heat has 

 to be absorbed by a pound of water than by a pound of earth to produce 

 a given rise of temperature. The net result is that the surface layer of 

 the water is warmed very much less than the land surface," and, as a result, 

 the air above the water is also warmed to a less degree. On the other 

 hand, at night time, a water surface radiates less heat into space than a 

 land surface under similar circumstances would do. Moreover, any cooling 

 which may take place at once calls into play convection processes in the 

 water itself. The cooled water becomes more dense and sinks, and warmer 

 water from below takes its place. Thus there is a great tendency for a 

 water surface to remain at a more or less constant temperature both by 

 day and by night, and for the changes of temperature due to changes 

 of season to be reduced in magnitude. This difference in the behaviour 

 of a water surface and a land surface has a most important climatic 

 effect. . . ." (R.G.K. Lempfert, op. c/Y., pp. 16-17.) 



Even more striking is the fact of hibernation, since it demonstrates the 

 folly of rash generalising and abstract deductive reasoning: 



"As far as mammals are concerned, the following are the principal 

 facts established: (1) All northern species, even those which find food 

 scarce during winter, do not hibernate, nor do all the species of the same 

 family, order, or genus. Even both sexes of the same species do not 

 always agree in this respect. The bear, the badger, the dormouse, the 

 hamster, the bat, the marmot, the zizel, and the hedgehog are among the 

 best known and most pronounced hibernators. But while all the burrow- 

 ing marmots, whistlers, woodchucks, ground-hogs, etc., are more or Jess 

 complete hibernators, the Alpine marmots indulge in this habit by fits 

 and starts. The sloth bear and other Indian UrsidaB differ from the other 

 members of their family in remaining awake during winter, though they 

 are sluggish during this season, moving about very little, and then only 

 occasionally when they require food ; and both the black and brown bear 

 of the Rocky Mountains and the polar bear are strict hibernators only 

 as regards their females, the male being often seen at large between 

 November and May. Most of the American squirrels differ from the 

 European species in being non-hibernating. (2) The same animal may 

 vary in this respect in different portions of its range. Thus, though the 

 American skunks are in the northern part of the region over which they 

 roam more or less complete hibernators, they get more and more wakeful 

 as their range extends equatorially, until in the most southern part of it 

 they move about freely at all seasons of the year. In like manner, the 

 prairie 'dog', or marmot, in the northern plains retires to sleep during 

 severe weather, as do also the woodchucks of the same region, but in 

 open winters and on pleasant days they display no such tendency; while 

 in the extreme southern limits of their range they are not hibernators 



