0Y8TEE CULTIVATION AT FALMOUTH. 181 



Judging from appearances, I certainly considered that the 

 first-named locality would produce the most successful results; 

 the ground being firm, and the currents, both on the ebb and 

 flood tides, being distinctly favourable for a heavy fall of spat in 

 that neighbourhood. During the closing days of September 1 

 visited this place at low-water with my assistant, but after a 

 most careful examination we were unable to detect any spat on 

 these tiles. The next day an attempt was made to examine the 

 remaining tiles, but the tide did not recede far enough to enable 

 this to be done ; and it was not till the early part of the follow- 

 ing year that it could be accomplished. 



On the morning of the 25th of February, I was able during 

 low- water to make a careful examination of these tiles and I was 

 excedingly gratified to find a fair sprinkling of oysters on most 

 of them. When arranging the tiles near Carclase point it 

 occurred to me to try, as an experiment, arranging some of them 

 in tiers, and I now found that the tiles in the second or third 

 tiers invariably had more young oysters on them than those next 

 the sea-bottom. This year I have profited by the experiment 

 and arranged all my tiles accordingly. 



I am inclined to imagine that the success of this method of 

 arranging the tiles, in tiers, is mainly due to the fact that crabs, of 

 the genus Portunus, do not take shelter beneath those of the 

 upper tiers, but invariably select the tiers next the ground. I 

 have never caught any species of crab flagrante delicto; but 

 I strongly suspect that all our literal decapods have a partiality 

 for young oysters. An observation made during the spring of 

 this year rather confirmed my suspicions. On that occasion I 

 was collecting in a large tidal pool in St. Just creek during low- 

 water, and I observed a specimen of Carcinus mcenas about three 

 yards from me, pick up a small Cardium edule with the right 

 chsela, and quickly retire with it beneath a heap of seaweed. 

 Luckily having a small landing-net in my hand I soon caught 

 the crustacean ; and although the mollusk was dropped, as soon 

 as the landing-net approached the crab, I secured it immediately 

 afterwards. This specimen of cardium measured 6 m.m. in 

 diameter. On my return to my -hut I placed both crab and 

 mollusk in a clean jar of sea-water, and kept both under close 



