INVERTEBRATES. WINDOW GROUPS 31 
Vertebrates include the largest, most powerful and most intelli- 
gent of animals. This group culminates in man, who still 
Alcove 12 bears witness to his chordate ancestry in the retention 
ates : . . : ; ; 
Taine of a chorda (cartilaginous spine), and gill clefts during 
Vertebrates embryonic life. Among these ancestral forms are the 
Ascidians, or Sea-squirts, an enlarged model of which is 
shown in the central case, while others are seen among the animals 
on the wharf-piles in the window group. Other models in the central 
case show the 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 tower and at its entrance show 
unusually large specimens, while a magnificent example of madrepore 
coral six feet in diameter is shown to the rear of the bust of Darwin, 
The associations of marine life found in the Bahamas are represented 
by several small groups in the center of the hall. 
Corals 
Here also four large models show the mosquito, which is the 
active agent in the spread of malaria. These models 
eee represent the insect enlarged seventy-five diameters 
Mosquito or in volume four 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 larvee 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 
eycle of the malaria germ in the blood of man and in the mosquito. 
In several of the aleove windows are habitat groups of inverte- 
brates illustrating the natural history of the commoner 
Window qi . : 
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. 8. Fish Com- 
mission buildings are shown in the background, represented by a colored 
photographic transparency. In the foreground the shallow water of 
; the harbor near the shore is represented in section to 
Marine Worm : : : 
Group 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 
