BUTTERFLIES FOR LONDON 
113 
During the first week of August, swifts, no doubt preparing 
for departure, were to be seen flying over the Serpentine in large 
numbers. On the evening of the loth the weather, which had 
been very damp and raw, suddenly changed, and on the next 
morning all the swifts had departed. The willow-wren was 
singing in Kensington Gardens on August 17 and again on the 
24th ; while on September 12 I heard the chiff-chaff, this being 
the only occasion upon which I have heard the song of this bird 
in a London Park in autumn. 
Some black-headed gulls appear to have taken to spending 
the night on the Serpentine, at any rate they have been staying 
later than they used to do. In previous years they all seemed 
to leave the Park regularly at sunset, flying away in a south- 
easterly direction. But last autumn at the end of November I 
often walked along the Serpentine after dark when returning 
home from my work and could usually hear the gulls quite 
clearly, although it was too dark to see them. I rarely come 
across anything of ornithological interest in London in December, 
but on the 3rd of this month I heard a missel-thrush singing 
loudly in Kensington Gardens close to the Magazine. 
February 28, igoi. A. Holte Macpherson. 
BUTTERFLIES FOR LONDON. 
OME of the public prints have lately advocated the 
introduction of butterflies into the parks and other 
open spaces in London, and have even gone so far 
as to say the authorities might take the matter in hand. 
That five or six kinds of our common and most beautiful English 
butterflies could be established in such places seems possible ; 
and the experiment, which would be an interesting one, might 
easily be tried. 
The following are to be especially recommended, as their 
food plant is the nettle, which keeps most creatures at a 
distance, and grows anywhere: the Peacock (Vanessa lo), the 
Lesser Tortoiseshell (Vanessa Urticce), and the Red Admiral 
(Vanessa Atalanta). The Vanessida and some few others live 
through the winter, and those that survive the ordeal of 
hybernation pair early in the spring and then lay their eggs. 
The most effective way, therefore, of introducing these 
insects into any locality is to catch and lay them down in the 
spring. Half a dozen boys armed with nets and duly initiated 
in the mysteries of sugaring, to which subtle art of the ento- 
mologist these butterflies are a certain prey, could easily collect 
a hundred or two in a few days. The captives, being hardy, 
might be conveyed by post in suitable boxes without serious risk. 
An attempt might also be made with the Large Tortoiseshell 
(V. Polychloros), which as a caterpillar feeds upon the Wych 
