touch an object with the point of its bill, whether in the act of feeding or of surveying the ground; and when shut up in a cage or confined in a room it may be heard, all through the night, tapping softly at the walls. The sniffing sound to which I have referred is heard only when the Kiwi is in the act of feeding or hunting for food; but I have sometimes observed the bird touching the ground close to or immediately round a worm which it had dropped without being able to find it. I have remarked, moreover, that the Kiwi will pick up a worm or piece of meat as readily from the bottom of a vessel filled with water as from the ground, never seizing it, however, till it has first touched it with its bill in the manner described. It is probable that, in addition to a highly developed olfactory power, there is a delicate nervous sensitiveness in the terminal enlargement of the upper mandible."
Professor Owen, in the 'Transactions of the Zoological Society,' vol. ii. p. 287, observes:—"The relations of the modifications of the skull of the Apteryx" (southern) "to its peculiar habits and kind of food are well marked and very easily traced;..... the anchylosed condition of all the parts concerned in the formation of the upper mandible is more complete than in the larger Struthionidæ, and relates to the greater force with which the beak is used in obtaining food. The nocturnal habits, combined with the necessity for a highly developed organ of smell, which chiefly compensates for the low condition of the organ of vision, produce the most singular modifications which the skull presents; and we may say that those cavities which, in other birds, are devoted to the lodgement of the eyes, are here almost exclusively occupied by the nose. The spinal column is relatively stronger, especially in the cervical region, than in the larger Struthionidæ."
Mr. Yarrell, in the 'Transactions of the Zoological Society,' vol. i. p. 72, in his article on Apteryx australis, makes the following observations:—The beak has "the upper mandible grooved on each outer side, near the margin, throughout its whole length; at the end of this groove, on each side, the nostrils are pierced, the apertures elongated and covered by a membrane, so suspended on the outside of each of them like a valve, that the slightest
