INVERTEBRATES. WINDOW GROUPS 43 



aquatic. The third model is of the adult male mosquito which IS Ii;iiimI< 



since ii never bites man. The fourth model shows the adult female mos- 

 quito in the attitude of biting. In another case is a series of models showing 



the life cycle of the malarial germ in the blood <>!' man and in the mosquito. 



In several of the alcove windows are habitat groups of invertebrates 

 illustrating the natural history of the commoner and more 



Window . . '. . 



„ typical animals. 



Groups • ' 



In the Annulate Alcove is shown the Marine Worm 



Group reproducing these animals with their associates in their natural 

 surroundings, as seen in the harbor of Woods Hole, Mass. The harbor 

 and the distant view of Woods Hole village with the U. S. Fish Commission 

 buildings are shown in the background, represented by an enlarged colored 

 photographic transparency. In the foreground the shallow 

 c water of the harbor near the shore is represented in section 



to expose the animal life found on muddy bottoms among 

 the eel-grass, as well as the chimneys of various worm-burrows. In the 

 lower part of the group a section of the sea bottom exposes the worms 

 within the burrows. Several species of these are represented. [See Reprint.] 

 In the Mollusk Alcove window is shown the natural history of a sand- 

 spit at Cold Spring Harbor, Long Island, including some of the shore 

 mollusks and their associates. The entrance of the harbor 

 °^ e is seen in the distance. In the foreground at the edge of 



Gr the sand-spit a mussel-bed is exposed by the receding tide 



over which fiddler-crabs are swarming into their burrows. 

 Beneath the water surface an oyster is being attacked by a star-fish, while 

 crabs and mollusks of various species are pursuing their usual activities. 

 The window group in the Vertebrate Alcove shows the piles of an old 

 wharf at Vineyard Haven, Mass. Below the low-tide 

 G - mark the submerged piles are covered with flower-like 



colonies of invertebrate animals. Among these are sea- 

 anemones, tube building worms, hydroids, mussels, sea mats and several 

 kind of ascidians or sea-squirts. The latter are primitive members of the 

 Chordate group which includes the vertebrates. Like the embryo of man, 

 they possess during their larval period a chorda or cartilaginous spine. At 

 first they are free swimming but later in life many of their organs degenerate 

 and they become fitted to a stationary mode of life. [See Reprint.} 



Other exhibits illustrate certain facts made clear by Darwin. On the 

 right and left of the entrance variation under domestication is 

 illustrated by dogs, pigeons, and domesticated fowls, the wild 

 Domestication s P ec i es from which they have been derived being shown in com- 

 pany with some of the more striking breeds derived from them. 

 The struggle for existence is portrayed by the meadow mouse, sur- 

 Struggle for rounded by its many enemies and yet continuing to main- 

 Existence tain an existence by virtue of its great birth rate. 

 [Return to the elevators.] 



