284 JELLY-FISH, STAR-FISH, AND SEA-URCHINS. 



distant injuries all round the globe neutralized one 

 another. 



** 5. Scraped a band of uniform width all the way 

 round the equator — same result as in 4. 



"6. Band of injury in same specimen was then 

 widened in the side facing' the direction of crawlino^ 

 — no effect. Still further widened — slii^ht chans^e 

 of direction, and, after a time, persistent cravvding 

 away from the widest part of the injured zone. 

 Repeated this experiment on other specimens by 

 scraping round the whole equator, and simultane- 

 ously making one part of the zone of injury wider 

 than the rest — same result; the animal crawled 

 away from the greatest aQnount of injury. 



" 7. Scraped on one side of the equator, and, after 

 the animal had been cravv^ling in a direct line from 

 the source of irritation for a few minutes, similarly 

 scraped equator on the opposite side — animal re- 

 versed its direction of crawling ; it crawled away 

 from the stimulus supplied latest. 



"8. Scraped a number of places on all aspects 

 of the animal indiscriminately — direction of ad- 

 vance uncertain and discontinuous, with a strons: 

 tendency to rotation upon vertical axis." 



These observations show conclusively that the 

 whole external surface, not only of the soft and 

 fleshy Star-fish, but even of the hard and rigid 

 Echinus, is everj^where sensitive to stimulation. 

 Closer observation shows that this sensitiveness, 

 besides being so general, is highly delicate. For if 

 any part of the external surface of an Echinus is 

 lightly touched with the point of a needle, all the feet, 



