of flesh which are then further cut up by the little teeth on the tongue, 

 or radula, which are placed farther back in the mouth. 



The eyes were large and wonderfully developed, and the Professor said 

 they were almost as complicated as the human eye, being made up of cor- 

 nea, retina, iris, pupil, and optic nerve. Just back of the eye, the ear, 

 or auditory organ, was placed, and was represented by a curved fold in 

 the head. 



The siphon was a conspicuous object, and was 

 placed on the lower or ventral side of the animal. 

 It was more or less conical in shape, and bent a little 

 outward toward the ventral surface. The aperture 

 was oval and large, and was provided with a valve 

 to govern the flow of water. 



Professor Parker said that the siphon is a valuable 

 organ to the animal, for it not only brings fresh water 

 to the gills, but by forcing water violently through 

 it, also serves as an organ of locomotion, enabling 

 the squid to shoot backwards very rapidly. 



The Professor next called our attention to certain small, dark brown 

 spots which covered the surface of the body and head. These he called 

 chromatophores, or pigment spots. Some of these spots were oval, while 

 others were irregular in outline, with many radiating lines 

 running into the surrounding parts of the body. In the 

 living animal, these little pigment spots, or cells, are con- 

 stantly swelling until the different spots touch each other, 

 and then contracting until they are scarcely visible. The 

 cells contain different colored pigments, and the effect of 

 these changes is to cause waves or blushes of different colors 



Beak of 



to sweep over the animal. The possession of this power of squid. Up 

 changing color is a great protection to the animal, for it is er mandibles 

 able to become the color of many objects upon which it 11 r a 



Sucker of squid, 

 h, horny ring sur- 

 rounding aperture; p, 

 pedicel, or stein; s, 

 cup of sucker. 



may be resting, and thus be rendered inconspicuous. This 

 is called protective coloration, and a similar power is possessed by other 

 animals, such as the chameleon, so common in Florida. In the octopus 

 the changes are more varied than in the squid, owing to its more seden- 

 tary habits. 



George inquired of the Professor whether the squid had a shell. For 

 answer he turned back a flap which projected over the head from the 

 upper or dorsal side of the squid, slit the thin skin of its inner surface, and 

 pulled out a long, thin, horny object, which he said was the internal 

 shell, or pen, of the animal, and served to support it in somewhat the 



128 



