102 Life, in its lower forms. 



own reward. From each of the avenues hundreds of 

 filmy tubes are seen protruding, which twist and twine in 

 all directions, as if seeking some object to lay hold of. 

 Nor do they seek in vain We are supposing that the 

 Star-fish has been laid upon his back. Well, the extre- 

 mity of one of his rays presently bends itself over, so that 

 the pellucid tubes can reach the bottom ;— they catch 

 hold ; the arm bends still more ; other tubes reach the 

 ground, and, in a minute or two, over turns the Star-fish 

 bodily, and is " as right as a trivet." 



See how gently and equably he is crawling over the 

 bottom, gliding uniformly along like a snail ! But how 

 does he do it '? What is the nature of his locomotion 1 

 Stay ! we shall see ; for he has reached the edge of his 

 prison- bottom, and is beginning to mount up the glassy 

 side. Watch him now, through the transparent medium, 

 and you will understand the secret. 



The flexible tubes, which look like so many caterpillars, 

 are seen to have dilated extremities, which, when brought 

 into contact with the glass, are made to adhere, just on 

 the same principle as a truant schoolboy makes his 

 sucker of wetted leather stick fast to the pavement. The 

 tubes are thrust out and drawn in at pleasure ; as the 

 Star-fish advances, new sucker-feet are pushed onward as 

 far as possible, where they adhere, and drag up the body 

 after them ; and by a succession of such apparently feeble 

 efforts progression is effected, - 



The mechanism of these sucker-feet is very simple. At 

 the bottom of the furrow or avenue in each ray are four 

 rows of minute pores, through which the suckers are pro- 

 truded. The base of each sucker is expanded into a little 



