30 Flashlights on Nature 



and swcUiiij^ buds, with growing bulbs or shooting 

 tubers, tlie temperature of the soil is sensibly 

 raised ; and this very heat, evolved by germination, 

 becomes itself in turn a cause of more germina- 

 tion ; each seed and root and bidb and sucker 

 helps to warm and start all the others. Spring 

 largely depends upon the warmth tiius produced. 

 The earth, during this orgy of growth, is warmer 

 by a good deal than the air about it ; warmer even 

 than it is in summer weather — indeed, were it not 

 for the number of plants which thus start growing 

 at once, growth would be almost impossible in 

 very cold countries. Like roosting fowls, they 

 warm one another. 



You think, however, the amount of heat that 

 can be thus evolved must be very insignificant. 

 By no means. Take an example in point. What 

 do we mean by malting ? We collect together a 

 number of seeds or grains of barley, we wet them 

 thoroughly, and allow them to begin germinating. 

 Each grain individually gives out only a small 

 amount of heat, it is true ; but when many of 

 them lie together, the total volume of heat pro- 

 duced is very great, and the amount would be 

 even greater if it were not artificially checked at 

 a certain stage : for the maltster does not wish his 

 malt to be *• over-heated." Malt, then, is nothing 

 more than sprouting barley ; and the heat it begets 

 in the process of malting shows us very clearly 

 how much warmth exists in sprouting seeds, or in 

 the growing portions of young plants, buds, shoots, 

 and tubers. 



