Note 51 — THE PRIMEVAL FORESTS OF CENTRAL AFRICA.

[Note 51] p. 220.—Hornbills.

Members of the family Bucerotidæ, including some 60 species whose generic arrangement is uncertain. Of their habits Prof. Newton says: “They breed in holes of trees, laying large white eggs, and when the hen begins to sit, the cock plasters up the entrance with mud or clay, leaving only a small window, through which she receives the food he brings her during her voluntary imprisonment”. He notes Mr. Bartlett’s discovery, confirmed by others, that the hornbills cast out at intervals the lining of their gizzard in the form of a bag, which is filled with the fruit that the bird has been eating, and asks whether “these castings are really intended to form the hen-bird’s food during her confinement”.