The Thrushes 37 
observed during the last five years (from 1920), that have not 
before been recorded. For instance, during the 1921 season 
four thrushes’ double-nests were found, following the finding 
of the fantails’ double-nest. 1 am in touch with over 60,000 
children by means of the School Journal, and am kept well 
posted by them in things that happen round about them. 
Thrushes’ nests have been found containing seven eggs, one 
containing eleven; these are probably instances of male birds 
with two or more mates, and it is suggested that the double¬ 
nests are instances of a similar kind; but this is not vet known. 
Moreover, nests of the thrush have been found containing 
two thrushes’ and two blackbirds’ eggs, and one containing 
four thrushes’ and four blackbirds’ eggs. Blackbirds’ nests 
have likewise been found with two blackbirds’ and two 
thrushes’ eggs. In one instance a thrush and a blackbird had 
nested about six feet apart in a hedge at Lower Hutt, and both 
nests contained two thrushes’ and two blackbirds’ eggs. It is 
difficult to learn how this comes about, but the most conclusive 
evidence has come from elderly unimaginative penple. One 
man saw a thrush sitting on the nest, and a blackbird settled 
beside her and waited to relieve her,—the blackbird taking the 
thrush’s place on the nest on her leaving it. Another elderly 
man, who lives in a whare at the edge of Maori bush and in 
the midst of English shrubbery, asked me one day if I thought 
it possible that the thrushes and blackbirds were crossing; and 
on my telling him of the facts that were being learned con¬ 
cerning the nesting, he said he believed they were actually 
crossing; they seemed to be nesting together, and he had seen 
young birds which he considered were neither thrushes nor 
blackbirds; he was sure they were a cross. It may be; no 
doubt such young would be infertile. An illustration is 
given shewing a thrush’s and blackbird’s nest built side by 
side. Another shews variations in the size and marking of 
eggs of some introduced birds. The variations may be signifi¬ 
cant, or they may not. New Zealand offers more favourable 
conditions for the birds than Britain, but no doubt variation 
goes on in Britain quite as much as in New Zealand, though 
