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PACIFIC SCIENCE, Vol. XIX, April 1965 
The adult colonies, however, do grow toward 
the source of light. This fact is especially obvious 
in caves or under overhangs where in semi- 
darkness the major branching is always in the 
direction of the light (Fig. 6). 
In addition, adult colonies have been trans- 
planted in calm water as shallow as 1.5 meters 
off Coconut Island, Oahu, where they have sur- 
vived for over 90 days. The light intensity at 
this point approaches 60% 3 of the surface light. 
On the other hand, the shallowest colonies of 
A. grandis in the natural habitat do not appear 
Approximately 475 gm cal cm- 2 24 hr -1 . 
Fig. 3. A living branch of A. grandis taken from 43 meters, transplanted in 12 meters of water off Moku 
Manu Islands, Oahu. 
