STRUGGLE EOR EXISTENCE. 



A similar table to the above, constructed for sal, will show that 

 that species lives between even wider limits of temperature than 

 teak, or, to speak more explicitly, can stand a lower degree of cold 

 and endure as much heat, provided the heat does not come in 

 blasts in the shape of hot winds, which, occurring, as they do, at a 

 season when sal is putting forth its new tender shoots, are fatal to 

 its existence. The Termmalia tomentosa cannot resist frost so well 

 as teak, but, as long as the temperature is above freezing, it can 

 stand more continuous cold and is thus able to extend several de- 

 grees further north, right up to the outer ridge of the Himalayas. 

 In Sindh, the chaors and kachas along the lower course of the 

 Indus are covered principally with babul, whereas higher up the 

 river frosts become very severe and tamarisk gets the upper hand. 

 In the Changa Manga plantation frost has killed out the babul and 

 left sissu complete master of the ground. 



But temperature does not only merely fix the limits within 

 which a species can live, but also influences the proportionate dis- 

 tribution of the various species forming a mixed crop ; for, while 

 all can live under the conditions of temperature obtaining in the 

 localit} r , some of the species will resist the extreme limits better 

 than others, some again will put forth greater activity than the 



*These figures have been obtained at observatories standing in the midst of in- 

 liabited Imilding.s and nt-'v.^arily situated on moderately high ground. The unni- 

 iiia temperature.-! out in the open country and in large gias&y expanses are without 

 doubt several degrees knver, a 1'pct that must bome in mind when reading the text. 



