[page] 17 

NOTES AND QUESTIONS ON POULTRY.

PERIOD OF INCUBATION OF CALL-DUCK.—Mr. C. Darwin is desirous of knowing the correct period of incubation in the call-duck, and if it differs from that of the common variety. I may add, that from careful observation I find the domestic duck's eggs hatch in twenty-six days, unless they have been allowed to cool, when it will sometimes be a day or two longer. Perhaps some of your readers may be able to state the exact time for hatching the eggs of call-ducks?—B. P. B.¹

¹ Darwin was gathering information for Variation chapter 8. A reply appeared in The Field (13 April 1861), p. 20: "TIME OF INCUBATION OF CALL DUCKS.—In answer to Mr Darwin's inquiry in THE FIELD, two weeks since, with regard to the time of incubation of the call duck, I find, that if the eggs have been carefully sat upon, twenty-seven days is the general time, and never more than twenty-eight days. I find the ducklings are very tender when young, and require a great deal of careful management till about four weeks old.—G. C. W." Bernard Philip Brent, (d. 1867). Bird fancier and author who often contributed to The Field and similar periodicals.