framework ^^ 



number of the vertebrae, the joints of the backbone, were 

 fused or consolidated into a single piece. This is called the 

 sacrum. Against that, on each side, was placed a bone called 

 the ilium-y and each ilium had on its under side a nicely made 

 bearing surface for the upper end of the hind leg. The 

 whole thing was, theoretically at least, rigid, and the system 

 of having the animal take off from a rigid hind end in 

 which no power was lost, and land on a flexible front end 

 which took up the shocks, was mechanically excellent. 



The weak spot in it was the articulation between the 

 sacrum and the ilium, the now notorious sacro-iliac joint. The 

 sacrum does not rest on the two ilia, it merely rests between 

 them, and the principal factor in holding the whole business 

 together is friction. Now, an animal that walks on four feet, 

 with most of the weight on the two front ones, can get along 

 this way all right, but when he tries to stand up on the two 

 hind ones, all the weight comes on that joint, and all the 

 shocks are received by it. The supposedly rigid mechanism, 

 being after all a "hand-me-down," sometimes shifts under 

 the strain. And when you or your friend turns up in the 

 doctor's office with a sacro-iliac sprain, you can blame the 

 fish, for it was his failure to provide a proper connection 

 between his pelvic fins and his backbone which is at the 

 bottom of the trouble. 



MUSCLES 



The fish's face is one of its notoriously weak features. 

 Even allowing for the fact that it was the first real face ever 

 attempted, little more can be said for it than that the mouth, 

 nose, eyes, and forehead — if such it can be called — are in 

 the proper order. It is of no use for frowning or smiling 5 

 if the fish could do these things, it would receive a great 

 deal more sympathy than it does. 



The reason that it cannot is that it has no facial muscles. 



