Here is basically a detached air cell. It’s
a saddle shape, it’s very distinctive. It comes down to join this bit of the air
cell which is still attached to the egg, but from here onwards it’s not attached.
So if you get an egg that looks like that when you candle it, what you’ve got
is a detached air cell. If it’s moving, if it’s floating as you candle the egg you
won’t get a hatch from it. If it’s not moving – if it’s this big and it’s not
moving – you’re still very unlikely to get a hatch. It’s a possibility but it’s very
unlikely. If it’s this big and it’s moving there really isn’t a chance of
any chick, even if it were to develop, no chance of a chick coming out of this egg.
OK, so here we have one of my other Sussex eggs – Light Sussex eggs – this egg is not fertile. So we can see the yolk here but there’s nothing inside
it at all. There’s some writing on the top which is my writing, but there’s
nothing inside it. There’s no eye, there’s no veins… So this chick is not
going to develop. But that’s not the reason why I’m showing you this
primarily. The reason I’m showing you this is because of the air cell. Now you
should be able to see, here, that there’s a light area just there. It looks like a
saddle and that’s a detached air cell. And on this egg it is completely
detached for quite a long way, so it spreads from there right the way around
to there. And if I move the egg I can see the air cell itself moving – so you might
have just caught that, there. Now quite often eggs that are posted, no matter how
well wrapped up they are, do have detached air cells. That’s the reason why
I try to pick eggs up for hatching if I can. But if they’re treated roughly in
the post – and of course we have no control over that – if they’re treated
roughly, despite the fact that these eggs were all labelled “Fragile” very carefully
and very well, then the jolting will detach the air cell. Eggs
are in quite a fragile state at that point. Sometimes in an egg were there is
a detached air cell, the chick will still hatch. But in this egg it’s become
completely detached. And you can tell that, a) by the fact that it’s spreading a
long way – it’s almost half the egg – and also because when I move it (I don’t know if the camera can pick this up really) but when I move it the air cell itself moves. It just
did it then – so this part’s moving. So if there were a chick in this egg it wouldn’t be hatching. I wouldn’t give it good chances to hatch at all.
Thanks for watching!