We're at the very last stages of incubation. The three days between now and hatching are critical to the chick's survival.
The yolk is being taken into the body more quickly today so the chick fills most of the egg.
If we could take a look inside, we'd see the chick has been slowly turning so that its head is close to the blunt end of the egg and the beak, usually tucked under one wing, comes to rest against the internal membrane.
The chick is now in the right place for hatching.
Between Days 20 and 21 the chick will 'pip' the internal membrane. Its lungs will inflate and for the first time it will draw breath from the air cell.
The air in that cell will sustain it until it's ready to break through the shell.
The incubated egg at day 19.
The chick is very nearly completely developed. The remaining growth relates to the yolk sac, which must be completely pulled into the body before hatch can take place.
The intestines are completely enclosed inside the body and by the end of today the yolk sac is about half ingested, so the chick looks bigger all the time.
The yolk sac, or 'vitellus', contains a complex system of major blood vessels. If the yolk sac is not fully absorbed into the body then neither are the blood vessels.
Trying to 'help' the chick out of the egg too early can cause those blood vessels to rupture and the chick to die.
We'll cover more about 'assisted hatching' later in this series.
No candling today!
This is all you'd see if you took the risk and candled today - but please note I candled this egg for demonstration purposes only.
It's very important that the egg is not candled between now and hatch. The chick needs to get into the right position so that it 'pips' (breaks through) into the air cell. If it tries to pip somewhere else it won't be able to breathe and will die.
Candling runs the risk of preventing it from doing the work it needs to do. It's not absolutely written in stone that moving the egg will cause the chick's death - I've candled at Day 19 to get photos without it having any ill effect - but it's a risk.
And in my view, it's a risk too far. Leave the eggs alone!
Although there's nothing to do today apart from the usual checks of temperature and humidity (remember - humidity levels should now be at around 65%), we need to start looking forward to what our chicks will need after they've hatched.
It's not that difficult ...
If you haven't done so already, you need to begin preparing those things now.
This period of incubation is a very vulnerable one. The chick needs to keep growing and at the same time position herself properly for hatch.
Any failures in cleanliness will have consequences now. The shell is very porous, having given a lot of calcium and water to the chick, and has in recent days been actively involved in exchanging gases between the chick and the outside world.
So it's very vulnerable to taking in external bacteria - from your hands, from the incubator, from your candler. Most late deaths during incubation are the result of various different bacteria.
If you've started off with a sterilised incubator and clean eggs, kept everything hygienic in the incubation process and your eggs at lockdown were well developed, your chances of a successful hatch are good.
On each day of this incubating series I feature a photo of one of my own chicks.
It helps us keep our minds focused on what we're working towards - a healthy, happy chicken.
This is Clyde, one of my bantam Lemon Millefleur Sablepoot chicks, at just ten days old. Note the wings, which are developing feathers quickly, and the feathering on the legs which are a special characteristic of this rare breed.
I've included a link all the way back to Day 1 of this series about incubation, in case you have found this page but missed out on the rest.
Click on any of these pictures to go to the page - and - Enjoy!
If you want e-mails personally delivered every day of incubation with a link to my pages telling you exactly what's going on during each step of the incubation process, you need to sign up for my series called "Hatching Happy Chickens".
If it sounds interesting to you and you'd like to know more, the image to the left is a link to details about exactly what you'll get.
And the best thing? - It's free (at the moment)!
Is there a question you'd like to ask about this stage of incubation?
Please feel free to leave a comment below - I'd love to hear from you.
The easiest way to follow my hatching series is to sign up for the e-mails. However, if you'd rather not do that, these are links you need to work logically through the series.
'The Incubated Egg' image is a commissioned artist's impression and, like all images on this site, is subject to copyright under the Copyright Law of the United States of America 1976. Under no circumstances is permission granted to copy or otherwise use this image.
All other images of candling on this and other pages are my own and are not to be used without permission.
If you wish to use these or any other images on this site for educational purposes you are required to contact me by using the form to be found on this page. For my full copyright policy see this page.