You take a fertilized duck egg and you bury it in the warm earth.
"A World by the Tale"
Gordon Randall Garrett
Very good cauliflowers have been grown by opening furrows, placing the fertilizer therein, and covering so as to form ridges; but I advise broadcast manuring and flat cultivation for this crop, as I am fully convinced that one acre in proper shape and condition will pay much better than two acres only half fertilized.
"The Cauliflower"
A. A. Crozier
So it is one thing to produce an egg from good, strong, vigorous stock during the winter in inclement weather, when all nature is against you, and so poorly fertilized that if it hatches at all, will hatch a chick so enfeebled in construction that no amount of petting or coaxing can induce it to live, but quite another to produce an egg so highly vitalized, that it will be sure to hatch a healthy young bird, bound to live under all circumstances.
"Natural and Artificial Duck Culture"
James Rankin