Fig. 123. Anterior limbs of vertebrates 



The limbs of the different classes of backboned animals are so distinct that most 



people never discover that they are all different forms of the same organ. W, the 



wrist : a, frog; b, partridge; c, man; d, bat; e, dolphin; /, blackfish 



Pituitary gland 



Thyroid gland 



Thoracic or 

 chest cavity 



Heart 



Diaj)hragm 



Suprarenal gland 



Abdominal cavity 



Fig. 124. The body cavity of man 



In the thorax, the part above the diaphragm, are located the heart and the lungs, 

 together with air vessels, blood vessels, and the part of the food tube connecting the 

 mouth with the stomach. In the abdomen, the part below the diaphragm, are located 

 the stomach, the liver (with the gall bladder), the small and large intestines, and 

 the reproductive organs, together with blood vessels and special ducts. The digestive 

 organs are not shown in this figure, but the kidneys, the bladder, and the connecting 

 ureter can be seen. (Courtesy of J. R. Bray Productions, Inc.) 



