XCV1 
Journal of Proceedings. 
about half grown, and were reared successfully. On two occasions during 
July, 1877, I took a pair of Ringdove's eggs and placed them in a Stock¬ 
dove’s nest, but both these birds easily forsake their eggs, and they did 
so in both these cases. About the middle of the same month I placed a 
Sparrow’s egg among the eggs of a Sedge Warbler, and she continued to 
sit as before until someone disturbed her. On nearly the same date I 
placed a young Sparrow, just hatched, among some young Swallows of 
about its own age. It was reared, and flew about the 23rd. On the 
28th I placed a young Sparrow in a Yellowhammer’s nest with eggs. It 
was fed, and afterwards left the nest as usual. 
About the middle of July, 1879, I put a Sparrow’s egg into a Swallow’s 
nest containing eggs. It was hatched about the 22nd, when the 
Swallows at once began to feed and attend to it, so that it left the nest a 
healthy bird about the beginning of August, but their own eggs became 
addled. 
I may mention that my friend, Mr. J. B. Ellis, of Leicester, placed 
some Rook’s eggs in a Magpie’s nest in April, 1878, but only one was 
reared, and the young bird did not afterwards build at the same spot, as 
Rooks are said to have done occasionally when placed in Magpies’ 
nests which happened to be built in a spot where it was desired to 
establish a Rookery. 
This spring I made several more interesting exchanges during the 
months of May and June. About the middle of May there were in our 
garden two Greenfinch’s nests-—the one with five recently-hatched young 
and the other with five hard sat eggs. I effected a complete interchange 
between the contents of these two nests, and, strange to say, neither bird 
deserted. The one to which I gave the young must have been greatly 
puzzled to account for all her eggs having hatched during an absence of 
a few minutes only, but she took matters as they came, adopted the 
young, and tended them till they left the nest. Her perplexities must, 
however, have been as nothing when compared with those of the other 
bird, whose young had apparently, to coin an expression, un-hatched 
themselves back into eggs again ; but, whatever she may have thought, she 
took matters contentedly, sat upon the eggs, which began to hatch next day, 
and the young were duly reared until they were nearly full grown, when 
some unknown person took them. A few days later I substituted four 
Sparrow’s eggs for four Greenfinch’s, in a nest in a hedge. These latter I 
put into another Greenfinch’s nest close by that already contained four 
—making eight in all. I next substituted four fresh Sparrow’s eggs for 
four h'ard-sat Greenfinch’s eggs in a nest in our garden. These latter I 
put into a Sparrow’s nest in a laburnum tree, taking the Sparrow’s out 
and putting them, with others (twelve in all, about equally sat upon) into 
another Sparrow’s nest in the same tree. Thus Iliad three Greenfinches 
sitting, respectively, on four Sparrow’s eggs, on eight Greenfinch’s eggs, 
and on four Sparrows’ eggs ; also a Sparrow sitting on four Greenfinch's 
eggs, and another on no less than twelve Sparrow’s eggs. Just a week 
later I ascertained that every one of these experiments were going on 
satisfactorily—that is to say, the birds were sitting on the eggs I had sup¬ 
plied them with, and would have reared the young all right had not various 
circumstances happened to prevent. The first batch of four Sparrow’s 
eggs before being hatched were sucked by a Cuckoo, while some of the 
second lot proved rotten ; possibly I had chilled them in the removal. 
The eight Greenfinch’s and the twelve Sparrow’s eggs turned out to be, 
some of them, more incubated than others, and after the first young were 
hatched the other eggs were neglected and became chilled. The Sparrow 
hatched the four Greenfinch’s eggs, and commenced to rear the young, 
but afterwards deserted them, perhaps on account of my disturbing her 
too often. 
