TWELFTH ANNUAL MEETING. 55 
tached, and the animal itself becomes attached to the shell, but 
in an entirely different place from where the first attachment 
was made. 
During this first period of attachment, when the shell itself is 
not firmly attached, but simply held firmly down to the sub- 
stance with which it is in contact, the young animal gets its food, 
or a portion of it, by means of a sort of proboscis, of elongation 
of the mouth part, which is capable of being moved about freely 
within the shell cavity. This proboscis stage lasts until the gills 
are fully formed and become of sufficient size to supply food to 
the animal, when the proboscis, or, rather, its flexible end, is 
transformed into the labial palps, which become closely con- 
nected with the gill-leaves. It will thus be seen that the life of 
the oyster can be practically divided into three portions. First, 
a free swimming condition which lasts for a longer or shorter 
time, in accordance with the temperature of the water, and dur- 
ing which time the young animal can move about with perfect 
freedom, although generally at or near the surface, and in a 
somewhat limited range. It is, during this stage, subject to the 
greatest dangers. Second,a condition when it is covered by 
a shell, is unattached, but is not capable of moving freely from 
point to point, except to whirl about, and thus roll arouna upon 
whatsoever substances it may rest; and third, its condition when 
attached to some permanent and stationary object, and including 
of course, the ‘proboscis stage.” During its first condition it 
can be affected by its own movements and the movements of the 
tides ; during its second condition, chiefly, if not solely by the 
tides, and during its third condition by neither, except in so far 
as the tides bring food to it in its resting-place. 
All efforts at artificial propagation should then take into con- 
sideration these three conditions. First, to guard it from escape 
during the first period; second, although perhaps not absolutely 
necessary, except in so faras it resembles tidal action, to move it 
about during the second period, until it can attach itself to some 
solid support; and third, to afford food for it during all periods. 
With the apparatus which I have described to you the first 
two ends were accomplished, that is with the aid of the syringe 
with which I introduced strong currents into the breeding vessel 
