338 BRITISH MAMMALS 



authorities to stamp it out among dogs. A bot-fly, called 

 Cephenomyia rufibarbis, attaches itself very specially to the red 

 deer. In outward appearance it mimics a bee, but of course has 

 only one pair of wings. This fly is found in Great Britain, 

 Germany, and wherever the red deer has its habitat. The flies 

 generally begin their attacks in May. These odious insects (an 

 adjective which can almost without discrimination be applied to 

 all insects) enter the open nostrils of the deer and squirt out 

 from their vent a drop of fluid containing a number of very 

 small, just-hatched maggots. These fasten themselves by hooks 

 to the tender skin inside the nostrils, and then by degrees 

 gradually wriggle themselves up the passage of the nose till they 

 reach the back of the throat. Their presence and the strong 

 irritation they provoke induce a great flow of mucus. On this 

 mucus they feed, and increase in size till they are over an inch in 

 length. Apparently the deer is generally able to eject these 

 grubs by coughing and sneezing, and only sufl^ers temporary 

 inconvenience by giving them this unwilling hospitality. When 

 they are coughed out they fall to the ground and become 

 chrysalides for two or three days, after which the perfect insect 

 emerges. IVIuch more serious results, however, come from the 

 attacks of a fly which is akin to the ox-warble. 



Red deer may be considered to have reached their maximum 

 development in size and numbers in Great Britain and Ireland 

 about the time when Julius Caesar invaded Britain. The 

 complete close of the Glacial ages a few thousand years before 

 had caused Great Britain to become a land of dense forests (only 

 broken by a few mountain tops, moors, chalk downs, and human 

 clearings) from the south of England northwards to Sutherland- 

 shire. Ireland, also, was much forested, especially in the south- 

 west and east. The megaceros had died out long before ; only 

 a few fallow deer lingered possibly in England. The roe deer 

 in Great Britain was no serious rival, the reindeer was extinct in 

 Ireland, and was being rapidly driven by the red deer into the 

 treeless desolation of the extreme north of Scotland and the 

 Orkney Islands. The assiduity of the Romans in England, no 



