The Star -Fish. 



29 



The four rows of suckers in each ray are on the ends of 

 the tube-feet. In alcoholic specimens these completely fill 

 the grooves, and in life they even extend beyond. The 

 star-fish moves about very slowly, stretching 

 out one ray as far as possible in front, plant- 

 ing a few suckers at a time, drawing the 

 body up to them, then lifting them and tak- 

 ing a fresh start. The tube-feet at the tip of 

 each ray are extended in front as feelers. 



Tbu sieve on the back coDnectB b; a tnbe with 

 limu in its walls, hence called the stone canal, with 

 a circular canal aronnd the moath, from which a 

 tabe extends down each ray. From these radial 

 tubes branches lead to each one of the small , mnsca- 

 lar sacs (Fig. 3, g) seen on the inside of the rays to 

 be connected with the tnbe - feet. These sacs and 

 some larger ones opening into the circular canal, act 

 as reservoirs for the water that enters at the sieve 

 and force it down into the tube-feet when the star- 

 FiG. 4 fish moves. One can fully understand and appre- 

 ciate this water-system of the star-fish only by see- 

 ing it in a specimen in which the tubes have been injected with 

 ooloriog matter. 



Down the middle of each ray a brown line, — the radial 

 nerve (Fig. 3,f), — will be seen on most of the specimens 

 ending at the tip of the ray in an eye. In life the five 

 little red eyes filled the tiny hollows at the end of the rays. 



The central part of the nervons system, as of the water-system, 

 is a cord around the month, occasionally seen on the dried animals. 

 The eyes of the star-fish see light only, as ours do when the lids are 

 closed. 



The star-fish has also the sense of smell. After one 

 has been kept without food for several days, it can be led 

 around the tank after a piece of shell-fish held just in 

 front of it with a pair of forceps, precisely like a hungry 

 dog after a bone. 



