72 BUSH DAYS 



spring-time. They do not migrate, as it is sometimes 

 supposed, but retire to the gullies and sheltered brush of the 

 mountains for the nesting season. The gill-birds, too, so dear 

 to the heart of the sportsman and gourmand, are plentiful 

 along the heathlands of the coast during the winter months, 

 but retreat to the recesses of the Blue Mountains in the spring, 

 there to build and bring out their young. It is strange that the 

 gill-birds should be so shy about their nests, when most of the 

 other members of the same family (the honey-eaters) build 

 quite openly in heathland and open forest. 



But then isn't all nature full of strange and inexplicable 

 things, about which even the most careful scientist can only 

 theorise? \Yho can understand the workings in the mind of 

 a small creature, which compel it twice a year to travel 

 thousands of miles, braving the elements and innumerable 

 dangers, without any absolute need? For the question of food 

 does not sufficiently explain this annual southern invasion and 

 northern flight. It is one of the many mysteries which are 

 always facing the naturalist ; the subject of migration opens a 

 wide field for observation on the part of the nature-lover, and 

 is a question in which the student, by quick perception and 

 careful watching, may give invaluable help to the scientist. 



