284 JELLY-FISH, STAR-FISH, AND SEA-URCHINS. 
distant injuries all round the globe neutralized one 
another. ide 
“5. Seraped 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 crawling 
—no effect. Still further widened—slight change 
of direction, and, after a time, persistent crawling | 
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 amownt of injury. 
“7. Seraped on one side of the equator, and, after 
the animal had been crawling 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 strong 
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 everywhere 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, . 
