I do not find in the works of either Macgillivray or Yarrell any mention made of the peculiar viscous saliva which is secreted by this bird, and which reminds one of what is observable in the case of the Wryneck and the different species of Woodpecker. It no doubt answers the same purpose, namely, to secure more easily the struggling insects upon which its existence depends. [Illustration: CUCKOO] THE CUCKOO. (_Cuculus canorus._) From numerous observations made by competent naturalists in different localities, it appears that the usual time of arrival of the Cuckoo in this country is between the 20th and 27th of April, and the average date of its appearance may be said to be the 23rd of that month, St. George’s Day. In no instance, so far as I am aware, has the bird been heard or seen before the 6th of April. On that date in 1872 it was observed at Torquay, but this was considered by my informant an unusually early date at which to meet with it. Between April and the end of August, it may be found generally distributed throughout the British Islands, even as far north as Orkney and Shetland. It is also a well-known visitor to the Outer Hebrides. On the European continent it occurs throughout Scandinavia and Russia, and is found in all the countries southward to the Mediterranean, which it crosses in the autumn for the purpose of wintering in North Africa. Eastward it extends through Turkey, Asia Minor, and Persia, to India, and according to Horsfield and Temminck, visits even Java and Japan.[97] The Cuckoo does not pair, but is polygamous. It is not unusual, soon after their arrival, to see a couple of male birds chasing a hen. The first eggs are seldom laid before the middle of May, or not until the birds have been here three weeks or a month. The egg, which is about equal in size to that of the Skylark, is very small, considering the bulk of the bird which lays it. It is white, closely freckled over with grey, or sometimes reddish brown, and generally has a few darker specks at the larger end. Instead of building a nest for itself, the Cuckoo deposits its eggs singly, and at intervals of a few days, in the nests of a variety of other birds, and leaves them to be hatched out, and the young reared, by the foster parents. The nests in which the Cuckoo’s eggs are most frequently deposited are those of the Hedge Sparrow, Meadow Pipit, Pied Wagtail, and Reed Warbler, but according to Dr. Thienemann, a great authority on the subject of European birds’ eggs, they have also been found in the nests of the following very different species:—