Vol. xlii.] 110 



♦fives us a partial answer to our question, " Do Cuckoos 

 always return to the same area?'' — for it is quite certain 

 that in this particular instance she does not. Mr. Burnett 

 in a letter to me writes : — " It is not always easy to find 

 these Cuckoos' eggs, although the birds are so numerous. 

 Prinia wanders about in the most extraordinary way : ono 

 year they haunt the gardens and compounds, another year 

 the outskirts of the railway cantonments, and another year 

 somewhere else. Where the Warblers go, the Cuckoos must 

 follow.'' 



I can only briefly refer to other Cuckoos which are still 

 in the initial stage of evolution and of which we may take 

 Cuculus canorus and its geographical races as typical. 

 Here we find that in England evolution has so far only 

 produced a nondescript kind of egg which goes quite well 

 with the eggs of Pipits, Wagtails, Reed-Warblers, etc., less 

 well with Robins, and in startling contrast with those of the 

 Accentor. But even in these we see some adaptation going 

 on. The eggs of Cuckoos laid with Wagtails (Box No. 1) 

 seem paler and more spotted than are those deposited with 

 Pipits and Reed- Warblers (Boxes Nos. 2 & 4), and amongst 

 the Hedge-Sparrows we find Mr. Owen's series of five eggs 

 showing a distinctly blue tinge. When we examine Conti- 

 nental eggs, we find adaptation to many fosterers such as 

 Acrocephalus and others much more advanced, and in 

 Finland we find an undoubted blue egg very frequently 

 deposited in the nests of Plioenicurus, CEnanthe, etc. In 

 India our birds have advanced yet a shade further. The 

 majority of eggs we get in the nests of Cisticola differ from 

 that of that bird only in size. With the Pipits we nearly 

 always find a dark reddish egg, whilst with the Suyas we 

 generally get a blotch}-- red type often much like that of the 

 foster-parent. In North- West India we get many blue 

 Cuckoos' eggs in the nests of Trochalopterum Uneatum and 

 Larvivora brunnea. Cuculus micropterus (Box No. 20) has 

 gone a stage further still, and, as far as we know at present, 

 lays blue eggs only, and these normally in the nests of birds 

 which also lay blue eggs ; finally, Cuculus saturatus (Box 



