The Zoologist — April, 1868. 1147 



one might indeed entertain doubts whether this variously-coloured 

 collection — these green eggs, with and without markings; these on 

 white, gray, green, greenish, brownish, yellowish, reddish and brown- 

 reddish ground; these gray-green, olive-green, ash-gray, yellow-brown, 

 olive-brown, yellow-red, wine-red, brown-red, dark brown and black; 

 these spotted, streaked, speckled, grained and marbled eggs — could 

 one and all be the eggs of our cuckoo 1 



And yet this is indeed the fact ! Many of these eggs, evidently so 

 widely differing, have long been known as cuckoo's eggs to our great 

 ornithologists and oologists, such as Naumann, Thienemann, Brehni, 

 Gloger, von Homeyer, Degland, &c. Every oologist knows that there 

 are some, which, both in colouring and marking, are extremely like 

 the eggs of the pied wagtail (Mo/acilla alba), the blackcap [Sylvia 

 atricapilla), the whitethroat (S. cinerea), the reed wren [Calamoherpe 

 arundinacea), the sky lark [Alauda arvensis), &c. "So much," says 

 Thienemann, in his beautiful work on eggs above mentioned (p. 84), 

 "so much do many of these resemble the eggs of the wagtail, the tree 

 pipit, the field lark and the great sedge warbler, that they can only 

 be distinguished from them by the distinctive spots and the grain." 



I shall return to these marks of distinction somewhat later; but now 

 we are concerned, in the next place, to find authorities for the esta- 

 blishment of the fact, that the cuckoo's eggs are in reality extremely 

 similar to several other eggs — I mean the eggs of those birds in whose 

 nests cuckoos' eggs are found; however superfluous such references 

 may seem to many an experienced oologist. Moreover, the Oology 

 of our days has made much more extensive discoveries in these 

 points. 



A cuckoo, which instead of its ordinary more or less clear third 

 tone, gave the second note of its cry in the fifth, with a shake on the 

 fourth, appearing again in the following spring (1850) with the same 

 remarkable cry, in the same isolated district, offered me an oppor- 

 tunity of investigating whether his species lived in monogamy, or in 

 polygamy, or finally in polyandry. Accordingly I visited almost 

 daily the district, which was very near me, but without attaining any 

 positive result. I observed, however, only one female, which seemed 

 to be paired with the above-mentioned male ; while a male which in- 

 habited a neighbouring district was driven away by the others as 

 soon as it passed beyond its own limits. Still the above-mentioned 

 male went frequently across a meadow to a little thicket, in which 

 I never heard another male, but from which I obtained a cuckoo's 



