276 THE ESSEX NATURALIST.
cabinet, the rarest variety being a set of 5, Dunmow, 24.5.22,
pale blue, unmarked eggs. Another species whose eggs are well
known for their variation is the Red-backed Shrike, a bird to
which Mr. Owen paid special attention. Drawer 15, large
cabinet, contains an excellent series of sets of this bird, some of
the sets differing so much that it is difficult to believe that they
belong to the same species. So vast is the amount of variation
to be seen in the collection that we can do no more than give
examples, and we mention only two more. In drawer 1, large
cabinet, will be found 34 sets of the eggs of the Chaffinch, which
range from the common reddish type to pale blue unspotted
eggs, and a remarkable Thrush-like set of 5, marked Little
Dunmow, 28.5.25. As an instance of extreme variability we
indicate a set of 4 pale green and almost unmarked eggs of the
Lapwing, marked Mundon Hall, 19.4.12.
The eggs of the cuckoo call for some attention. They repre-
sent seventeen fosterers, most of the eggs coming from the nests
of the Hedge-Sparrow and Pied Wagtail. Among the less
usual fosterers may be mentioned the Blackbird and the Song-
Thrush. Three eggs of the same Cuckoo were laid in the nests
of the Hedge-Sparrow, Greenfinch and Linnet and there are
several instances of two Cuckoo's eggs having been laid in the
same nest. To explore and debate all the problems that are
met in a consideration of these eggs would result in an article
of inordinate length, so we conclude with the mention of those
which specially attract attention. The single egg of the Mediter-
ranean Black-headed Gull, which differs from the Black-headed
Gull which breeds in Essex in as much as its head is black
instead of brown and it has a different cry, is of historical
interest, as the egg was collected in Asia Minor by that remark-
able man and naturalist, the late F. C. Selous. Occasionally
one species will lay, seemingly without reason, in the nest of
another. There are several examples in the collection, including
the following : a Stock Dove's egg with four of the Jackdaw,
a Wood Pigeon's egg with four of the Sparrow-Hawk, a Black-
bird's egg with two of the owner in a Linnet's nest; two Black-
bird's eggs were found in the nest with 5 eggs of a Song-Thrush
and we are told that the latter had the mastery. A curious
story surrounds two Yellow Bunting's eggs, each egg being a
separate set or laying. The eggs were laid in 1925 by the same