32 FIRST FLOOR, SOUTHEAST PAVILION 



diversity of forms which it embraces, including marine, fresh water and 

 land animals. All mollusks have soft bodies, but nearly all of 

 M Husks them secrete a shell which in many species is of pearly mate- 

 rial (mother-of-pearl). Well-known examples of this group 

 are the common clam and oyster and enlarged models in the 

 Model of center case show the anatomy of these species. The largest 

 n species is the huge " bear's paw" or furbelowed clam of the 



eastern seas. 

 Vertebrates include the largest, most powerful and most intelligent 

 of animals. The group culminates in man who still bears 

 V t h t witness to his chordate ancestry in the retention of a chorda 

 and gill clefts during embryonic life. The models in the 

 central case show the development of the egg of typical vertebrates. 



An exceptionally large specimen of beautiful madrepore coral is in the 

 case near the entrance, and the associations of marine life that may be found 

 r , among the coral reefs of the Bahamas are represented by 



several smaller groups in the center of the hall. Certain of 

 the groups in this section of the hall illustrate various biological principles 

 associated with the name of Darwin. The variation in form, size and color 

 of the snail and the variation of the shell of the common scallop are 

 graphically shown. 



4 Arwphe/es, CuJex 



BODY AT AN ACUTE ANGLE TO THE SURFACE BODY PARALLEL TO - 



ON WHICH THE INSECT RESTS, ON WHICH THE INSECT 



Characteristic resting positions of malarial and common mosquitoes 



Four large models in the center of the hall show the mosquito which is 

 the cause of the spread of malaria. These models represent 

 Models of the insect enlarged seventy-five diameters or in volume four 

 the Malarial hundred thousand times the natural size. The mosquito in 

 { its development undergoes a metamorphosis. The model 

 at the left shows the aquatic larval stage; the larvse are the "wrigglers" 

 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. In another case is a series of models showing the 

 life cycle of the malarial germ in the blood of man and in the mosquito. 



[Return to the elevators.} 



