X CASE ILLUSTRATING "BIRDS" 143 



large label — " Aves." Below this are three of the 

 most typical yet most dissimilar birds. An enormous 

 albatross, typical of flight, spreads its wings from 

 side to side of the bay. An apteryx, flightless, and 

 adapted only for running on the ground, stands on 

 one side ; and a penguin, adapted only for swimming 

 with legs and wings — mainly living in the water — 

 illustrates the other extreme. In a case on the left 

 are the skeletons and parts of skeletons of the typical 

 birds ; also the eggs of birds, and a complete series 

 of the development of' a number of chicks, all of one 

 hatch, at different ages. Heads, beaks, feathers, 

 down, wings, ears occupy another case, the series 

 of feathers and feather structure being of exquisite 

 beauty. In another case are the organs, nerves, 

 muscles, and the modifications of feet for seizing, 

 swimming, scratching, perching, or climbing. 



The introductory collection to the " fish " was 

 carried forward and that to the " insects " begun in 

 this year, and a start was made with the striking 

 cases in the central part of the hall illustrating 

 general laws, such as protective mimicry, variation 

 under domestication, and conformity to environment. 



The case in which are the hybrids between the 

 carrion crow and hooded crow and those showing 

 gradation between two different forms of goldfinch 

 were formed in this year, as were those showing 

 what selective breeding has done in producing 

 many marked breeds of pigeons from the common 

 •" blue rock." 



