478 JOURNAL OF SCIENCE. 
Dee. 17, in a nest of G. flaviventris, with young cuckoo only 
18, S %. cuckoo egg only 
19, i . 1 egg of dupe 
23, a Re young cuckoo only 
Jan. 1, >» ' ” ” 
6, “ 4 cuckoo egg only 
From the foregoing table, the outcome of much persevering research, 
it may be observed that this cuckoo nearly always makes use of the 
nest when it contains eggs, a pledge it will not be lightly abandoned 
by the dupe. Also that the young cuckoo becomes the sole tenant of 
the nest.* Z. lateralis is marked with a ? because the writer can not 
assert it as a fact that this bird is the dupe of the cuckoo, the 
probability has been pointed out for the consideration of naturalists; 
in the meantime the four eggs found have been carefully preserved 
for reference. It is worth recording that all of the nests mentioned 
were built in manuka (Leptospermum). I have the egg from a nest of 
G. albofrontata taken at Wharekauri in the Chatham Isles. The 
whistler has been constantly observed here fed by warblers during 
the months of December, January, till Feb. 9th, the latest dated 
entry. Whilst so being fed, there is often an attendance of tuis, 
bell-birds, yellow-breasted robins, and white-eyes, occupying the 
neighbouring branches; of these different species, the bell-bird is 
perhaps the most persistent in following the almost ceaseless cry of 
the young cuckoo. In January, 1865, a pair of Petroica macrocephala 
acted the réle of foster-parents to a whistler. The egg is elliptical, 
very delicate in texture, of pale greenish dun, sometimes with an 
olive-brown smear; pale greenish-white, smeared with olive-brown ; 
olive-brown; dark greenish brown; bluish-white, smeared in places 
with pale olive-brown; clear bluish-green. The two eggs last 
described exceed all the other specimens in size: the bluish-green 
ege was taken from the above-mentioned nest of Zosterops lateralis. 
Average size in length is 9 lines; with a breadth of about 6 lines. 
I have known but of one whistler’s egg to be found broken in the 
nest, this fact seems rather remarkable considering the thinness and 
fragile character of the shell, the distance from the entrance to the 
bottom of the interior of a warbler’s nest; and again one asks the 
question how is the cuckoo’s egg deposited? Before the bird quits 
the nest, it is fairly well feathered; it is easily found by means 
of its almost incessant cry, even if the excited and rapid movements 
of the foster-parents fail to attract attention. It may be proper to 
refer to the rapid changes that take place in the plumage of the 
young birds; a specimen obtained in the Malvern district on March 
13th had nearly the whole of the upper plumage of a deep green, the 
bronze which distinguishes this part in the adult appeared very 
slightly on the occiput, back, and at the carpel flexure; the forehead 
mottled with white, which extended almost to the eye; the throat and 
fore-neck mottled with brown; on the breast’ and abdomen bars were 
developed, but without the lustre of the adult; the mandibles were 
less curved, the lower one of light horn colour, except at the point 
and along the centre, where it was blackish. Another specimen 
obtained from the Plains a few weeks later (April 2), had the upper 
plumage of bright metallic lustre with bronze on the hind neck; 
*See Trans. N.Z. Institute, vol. V., p. 178. 
