28 Bulletin Wisconsin Natural History Society [Vol. 11, Nos. 1-2 
On the other hand soft bodied animals without any skeleton are 
often able to stand dessication and marked changes in temperature 
without apparent harm. On one occasion a Metridium was left ex- 
posed to the direct rays of the sun on a vertical rock surface, because 
the seaweeds which usually covered it had been left in an unusual 
position by the falling tide. A thermometer beside it registered 
23.4° C. and it was thus exposed for at least three hours; at the 
end of that time it was covered by the ocean (7.9° C.) and at 
Fig. 25. Showing Several Anemones, Metridium marginatum, left out 
of Water at a Low Tide. 
Six with their bodies more or less expanded are in the lower left hand 
corner; one expanded individual (white) is in the center of the picture just 
above the light mass of Chondrus ; three contracted individuals are at the 
surface of the water on the right side. 
once extended its tentacles. Five days later this individual was 
in the same position and apparently in good condition. Metridia 
were often observed to be exposed (fig. 25) under similar con- 
ditions. The body was usually extended and filled with water; 
the tentacles were contracted. 
The food relations of the animals on the rock beaches were 
studied as fully as possible and notes concerning food habits 
