HABITS OF MARINE ANIMALS — 145 
The scallop detects the shadow of the passing skate 
by means of several eyes arranged in a row along the 
border of each mantle, just under the valves. In 
Pecten maximus, the bivalve under consideration, there 
are from eighty to one hundred and twenty of these 
eyes, and nothing is more beautiful in marine life than 
the two circular rows of eyes, sparkling like precious 
jewels. 
When photographing the scallop shown I had to be 
very careful not to let my shadow fall on him, or he 
would instantly have shut up, and I should then have 
had to wait at least half an hour before he had again 
fully opened. 
Next, as to how the scallop opens and shuts. The 
two valves work on a hinge, and when the pecten is at 
rest these valves gape open. They are closed by the 
contraction of a strong muscle which is attached to 
each of them on their inner surface. 
There are several movements which the pecten is 
able to perform. It may jerk itself back a few inches 
from some irritating object, it may rise from the bottom 
and swim in a characteristic manner (as if taking a 
series of bites out of the water), and if in good health 
it will always right itself in a few seconds or minutes 
when turned over on its flat valve. 
It was my good fortune to meet Dr. Dakin, of 
Liverpool University, who has made pecten a subject 
of special study, and with his assistance I was able 
to take a photograph of this act of turning over, and 
K 
