ERIC MJOBERG, ISOPTERA. 



119 



explained as an adaptation to the climate. The nest being 

 built of a more brittle material tban other ground nests 

 (which as a rule have a thick cover or cemented clay and 

 sand) certainly runs a great risk of being blown down, as 

 even with its present shape not seldom seems to happen 

 when the violent northern storms blow. Its narrow flattened 



Photo E. Mj Öberg. 

 Text Fig. 63. Nest of Eutermes futnipennis Walk. from N. S. W. 



shape is very likely an adaptation against the very hot 

 sun. A nest of this shape apparently does not absorb so 

 much heat as do the more conical or flattened ground-nests. 

 These latter are so hot in the raiddle of the day that one burns 

 one's hand when one touches the outer wall. The interiör 

 parts are so hot that the termites themselves cannot stånd the 

 immense heat, but all disappear from the parts of the nest 



