[37] OYSTER CULTURE IN MORBIHAN. I79 
tive, for the crab drags it about as a galley-slave does his ball, and it is 
a damaged oyster for the culturist. But, fortunately for itself and for 
us, the oyster is not quite so foolish as it seems to be, and is not often, 
taken. J have almost always seen the crab pay the penalty. When they 
cannot do injury in this manner, they have recourse to another method, 
which is as follows: 
‘““Whole groups of crabs unite together and dig holes, as large some- 
times as a hand-basin, first using their claws, and then, when the holes 
become too deep to work in in this way, loading the mud or muddy sand 
upon their bodies and discharging it beyond the hole, thus burying all 
the oysters in the vicinity. By the action of the waves, oysters are often 
thrown into these holes and buried in them; this we tried to prevent 
by means of long-handled rakes. I neglected to state that the basins 
or holes dug by these sea-moles, the crabs, serve as a shelter for their 
progeny. 
‘¢Since I have spoken of the crabs, I will pass in review the other ene- 
mies of the oyster, which are the more to be feared; this is a matter of 
great interest to all. 
“ Murex tarentinus is furnished with a small apparatus, in the form of 
a rasp, armed with very sharp points, harder than diamond, with which 
it pierces and kills the oyster. This is a parasite of the most dangerous 
sort. I placed someof them upon collectors covered with young oysters, 
and saw the adults pierce the oysters, one after another. They did not 
leave the collector until they had killed the last one. Ordinarily it is 
the young Murex that attacks the young oysters, which they can pierce 
when they are scarcely the size of a pin. ‘The older ones attack the 
larger oysters, and thus each has his field of destruction. To get rid of 
these dangerous parasites, they must be driven off at all times, but espe- 
cially at the spring-tides of April and May. 
“A mostactive search should then be made of the lower levels of the park, 
where all the stones, tiles, and wood-work should be moved, overturned, 
and inspected. Even the oysters themselves #Ad the dead shells should 
be subjected to this examination. In the inspection made at this season, 
they are always to be found in groups of fifteen or twenty, and search- 
ing more closely about these groups, their eggs are often to be found. 
The eggs alone may even be discovered after the spawning season is 
over. These eggs look something like large grains of wheat; they are 
placed in an upright position, very firmly fastened at the base to the 
solid body upon which they have been deposited. The number of eggs 
in each cluster often amounts to several hundreds, and each egg contains 
at least thirty-three embryos. There is no need of my demonstrating 
further the importance of destroying both the Murex and their eggs. 
After hatching, the cluster of eggs continues to present the same appear- 
ance for a long time, and it is only by a close examination that an 
_almost imperceptible opening on the top of the egg can be discovered ; 
then it is too late to destroy them. 
