294 ANDREW JACKSON HOWE. 



part of bivalves holds the shells so snugly in contact, 

 that it requires the force of a lever oyster knife to 

 pry them apart. 



Among articulate animals is the lobster; its skele- 

 ton, like an armor, is on the outside ; and in this re- 

 spect it is quite the antithesis of vertebrates. This 

 skeletal peculiarity renders the creature rather clumsy. 

 The fossil trilobite was the lobster's tribal ancestor, 

 but perished in Silurian seas. 



The student of zoology is of necessity a lover of 

 living things. The ugly toad has a jewel in its head, 

 that is, it has something in its being which we may 

 stud} 7 with interest and profit. When the toad licks 

 up a fly its tongue moves with the rapidity of light- 

 ning. In fact the act is accomplished in our presence 

 and we do not observe the motion. The insect does 

 not fly away, yet disappears ; soon a motion of the 

 toad's throat indicates that food is swallowed. A frog 

 is fairly quick in its attempts to catch prey, but the 

 tongue has little to do with the capture. If we could 

 understand the activities of the lingual plexus of the 

 toad, a step would be taken in the science of neurology. 

 It is easy to comprehend how speed is derived in a ser- 

 pent's head when the reptile inflicts a poisonous bite, 

 for the recoiled head and neck, through a series of 

 toggle-joints, can plunge forward a foot as quickly as 

 an inch could be compassed. The anatomy and func- 

 tions of a serpent's organization are marvels of adap- 

 tation of means to ends. That a limbless creature can 

 attain the speed of a horse is quite astounding. If a 

 snake be placed upon a polished floor, it may wriggle 

 in serpentine curves, but no headway is made; but 

 lay a brick here and there, and the worried reptile will 



