36 



POPULAR SCIENCE MONTHLY. 



lift its body by means of the paired fins, and these would then serve 

 after the fashion of the arms and legs of a quadruped as the fish 

 ' walked ' slowly about;, alternating the forward and backward move- 

 ments of its extremities. This condition is illustrated in Fig. 4, in 

 which the bend of the arms and legs, where they support the weight of 

 the fish is shown satisfactorily. In this figure^, which, together with 

 Figures 5 and 6, were photographed from almost directly above the 

 fish, one observes that the strain upon the limbs falls, not upon their 



Fig. 4. 



Fig. 5. Fig. 6. 



Lung-fish showing Vakious Movements. 



tips, but near the middle. Thus one notes in Fig. 6 that the tip of 

 the right-hand pelvic limb curls upM^ard and is free from the bottom. 

 One observes especially in Fig. 3 the stress upon the left pectoral limb, 

 which causes it to be bent almost at right angles in an elbow-like fash- 



