VII] 



THE FUNCTIONS OF THE SKIN 



87 



atmosphere (such as a horse deck on board ship) may shed their 

 winter coat in a few days although the outside temperature 

 may be below freezing : similarly if taken to a cold locality from 



Fig. 44. Icelandic ponj* showing ' tail-lock ' (from Ewart). 



a warm climate the hair responds by gro\\ing longer. There 

 are however temporary exceptions to this rule for horses after 

 crossing the Equator may take a year before adjusting the 

 length of their coat to the changed conditions. There are some 



