Carl's Roost:
Day 14 Observations
The chicken has grown a LOT since Friday. It now
is as long as the egg is wide. It is not moving as
far as it was on Friday - it's running out of room!
But it is still moving enough that most images are
blurred.
The egg compartments have changed a lot too. There
no longer is an identifiable yolk. The chick is
enclosed by a large dark chamber (amnion? - how did
it get so big?) which has little droplets of some
other material in it (waste products?). There are
two compartments at top and bottom which are
brighter. Are these albumen? Or something new?
How could you investigate this?
MRI: Front view series.
Here are 4 frames from the front view series.
Check out how long it took us to get these! (Look
at the database list for the times). You can make
out a few body parts. I am speculating a bit about
the wing - it is in almost the right place, but
seems to be at an awkward angle.
Note the heart and blood vessels, and the
associated movement artifacts. Even when the chick
holds still, its heart beats.
Compare the positions of the eyes, "wing", heart
with the position as seen in the side views, below.
Do my interpretations agree with each other?
Remember the chick may have moved, but not too
far.
MRI: Side view series.
Here are 3 frames from the side view series.
Notice the bilateral symmetry of the body - it isn't
perfect because the chick is not perfectly aligned
with the slice, but (especially in frame 139) you
can see matching structures on right and left sides
of the body. Note particularly the two thin
diagonal black objects at EF-45, and FG-5. Also In
frame 144, there are two lighter spots on either
side of the "keel" (at upper left corner of E6 and
lower right corner of D4.) These might be related to
the wings.
The keel is the point of attachment for the flight
muscles.
C.D.Gregory: April 29, 1996
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