INVERTEBRATES. CRUSTACEANS AND INSECTS 33 



tral forms are the Ascidians, or Sea-squirts, an enlarged model of 

 Alcove 12 which is shown in the central case, while others are 



Chordates seen among the animals on the wharf-piles in the win- 

 Including dow group. Other models in the central case show the 

 Vertebrates development of the egg of typical vertebrates. 



In the circular tower alcove in the southeast corner of the hall is a 

 comprehensive synoptic series of stony corals. Central cases in this 

 r , tower and at its entrance show unusually large speci- 



mens, while a magnificent example of madrepore coral six 

 feet in diameter is shown to the rear of the bust of Darwin. The associa- 

 tions of marine life found in the Bahamas are represented by several 

 small groups in the center of the hall. 



Here also four large models show the mosquito, which is the active 

 Models of agent in the spread of malaria. These models represent 

 the Malaria the insect enlarged seventy-five diameters or in volume 

 Mosquito f our hundred thousand times the natural size. The mos- 

 quito in its development undergoes a metamorphosis. The model at 

 the left shows the aquatic larval stage; the larvae are the "wigglers" of 

 our rain-water barrels. The next model is the pupal stage, also aquatic. 

 The third model is of the adult male mosquito, which is harmless, since 

 it never bites man. The fourth model shows the adult female mosquito 

 in the attitude of biting. It is so arranged as to show the internal organs, 

 thus illustrating a typical insect anatomy. In another case is a series of 

 models showing the life cycle of the malaria germ in the blood of man and 

 in the mosquito. 



In several of the alcove windows are habitat groups of inverte- 

 Window brates illustrating the natural history of the commoner 



Groups and more typical animals. 



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 a colored photographic 

 transparency. In the foreground the shallow water of the harbor near 

 Marine Worm the shore is represented in section to expose the animal 

 Group fife 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. 



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 



