STAR-FISH AND SEA-URCHINS. 321 
On removing with a pointed scalpel the eye-spots 
from a number of Star-fish and Echini, without 
otherwise injuring the animals, the latter no longer 
crawled towards the light, even though this were 
admitted to the tank in abundance; but they 
crawled promiscuously in all directions. On the 
other hand, if only one out of the five eye-spots were 
left intact, the animals crawled towards the light 
as before. It may be added that single detached 
rays of Star-fish and fifth-part segments of Echini 
crawl towards the light in the same manner as 
entire animals, provided, of course, that the eye-spot 
is not injured. 
The presence of a sense of smell in Star-fish was 
proved by keeping some of these animals for several 
days in a tank without food, and then presenting 
them with small pieces of shell-fish. The Star-fish 
immediately perceived the proximity of food, as 
shown by their immediately crawling towards it. 
Moreover, if a small piece of the food were held in 
a pair of forceps and gently withdrawn as the Star- 
fish approached it, the animal could be led about 
the floor of the tank in any direction, just as a 
hungry dog could be led about by continually 
withdrawing from his nose a piece of meat as he 
continually follows it up. This experiment, how- 
ever, was only successful with Star-fish which had 
been kept fasting for several days; freshly caught 
Star-fish were not nearly so keen in their manifesta- 
tions, and indeed in many cases did not notice the 
food at all. 
Desiring to ascertain whether the sense of smell 
