142 THE GROUSE IN HEALTH AND IN DISEASE 



confused with the dark, red-brown, winter heather, which is 

 secure from any ordinarily severe frost, and is merely the 

 resting condition of the healthy living plant. The two are 

 totally distinct in colour, the former being, as has been said, 

 brick-red or fox-red, and the latter a deep brown, or dark 

 reddish brown often associated in the leaves of the other side 

 of the twig, with a deep or vivid winter green. Such heather 

 is alive and healthy, and forms perfectly wholesome food for the 

 Grouse ; it is, in fact, their staple winter food. The only point 

 is that being somewhat dry and sapless (in which lies the whole 

 reason of its immunity to frost), and lacking in food- value 

 when compared with fresh, young, summer heather, about three 

 or four times as much has to be eaten by the bird to get the 

 same amount of nourishment. This dark, winter heather 

 cannot be correctly called " frosted," since the change in it 

 is merely due to a seasonal alteration in the chemical condition 

 of the cell contents, while it remains in the healthy resting winter 

 state. With certain modifications it may be stated generally 

 with regard to the two forms of " frosted " heather that in 

 one case the heather is dead having been killed by even a 

 moderate frost and that in the other it is living, and is proof 

 against even a severe frost. 



The presence or absence of snow on the ground makes a 

 great difference in time of frost. Snow acts as an efficient 

 protection to the heather, and only the extra long twigs that 

 protrude beyond the snow are affected by frost. Hard frost 

 after snow trims the heather by cutting off and killing all the 

 longer pieces, so that the leaves bleach whitish grey, and 

 eventually drop off. This may happen even to straggling 

 pieces of dark brown winter heather if the frost is severe 

 enough ; but it requires a very low temperature and a pro- 

 longed exposure to affect real winter heather to any great extent. 

 There is no other condition of heather which can with any 

 show of reason be called " frosted " ; and it may be urged 

 that no heather should be so named except that which has 

 been nipped and killed beyond all chance of recovery. To call 



