NATURAL HISTORY NOTES, QUERIES, &c. 79 
subject, and this, I fancy, has been overlooked by your correspondents. In 
Letter XX. (February 26th, 1774), to Uaines Barrington, he remarks: “When 
they [the sand martins] happen to breed near hedges and enclosures, they are 
dispossessed of their breeding holes by the house-sparrow, which is on the same 
account a fell adversary to house martins.” Also in I.etter XXI. to the same 
gentleman, dated September 28th, 1774, ha says, “ I have suspected that they 
[the swifts] sometimes usurp upon the house-sparrows and expel them, as sparrows 
do the house and sand-martin ; well remembering that I have seen them squab- 
bling together at the entrance of their holes, the sparrows up in arms, and much 
disconcerted at these intruders.” 
G. W. Kirkaldy. 
Horse Chestnut Buds. — Those who read the delightful description of 
horse-chestnut buds (p. 46) will be interested to know that if they are gathered 
before they open and put into water they will gradually unfold and develop both 
leaves and flower buds. The bud at the tip of a branch which I put in water in 
the middle of January has now four leaves and a spike of flower buds. The first 
pair of leaves measures eight and a-half inches from tip to tip, and the second pair 
rive and a-half inches. Another branch, though its leaves are less advanced, has 
grown three and a-quarter inches, and the flower stalk has about 100 tiny buds 
on it. Many other buds, especially hawthorn, lime and sycamore, open freely in 
water, but the horse-chestnut is best. 
Philip Jones. 
A Census of London Rookeries. — It has often struck me that the 
London members of the Selborne Society would be doing a useful piece of work 
if they would accurately note the number of rooks’ nests in the various small 
rookeries that still exist within the area covered by the London Directory. Only 
nests that are inhabited this year should be counted, and if the results were sent 
to the Editor of Nature Notes by the middle of April, there would still be time 
to compare the various reports, and, if necessary, verify them before the leaves are 
out. Then I would further suggest that the results should be published from year 
to year : and I am sure that the facts thus collected would be of interest. For the 
rook population fluctuates in a very curious way. Since the trees were felled in 
Kensington Gardens— I think in 1881 — I have noticed no nests there till last year, 
when one was built near the north end of the Broad Walk, but was soon deserted, 
and another near the south-west corner of the gardens. At the present time, how- 
ever, there are, I believe, eleven nests in process of building near the north end of 
the Broad Walk, and it is an interesting question where the rooks have come from. 
They must have migrated from the country districts ; and what can have led them 
to do that? Other spots to which I should like to direct the attention of your readers 
are the grounds of Chelsea Hospital, where several pairs were building last year ; 
Church Street, Kensington, where one nest was built last year, but was soon 
abandoned ; Holland Park (where a pair of magpies were also noticed last year) ; 
Albion Street, north of Hyde Park, where there was one nest last year, and where 
two or three are being built now ; Connaught Square, which had five or six nests 
last year ; the Marylebone Road, where a dozen years ago there used to be at 
least a dozen nests ; Gower Street, at the back of which one or two nests existed 
not long ago ; and lastly, the well-known colony in Gray’s Inn. 
J. S. M. 
OFFICIAL NOTICES. 
Excursion to Selborne. — It is hoped by the Council that the travelling 
expenses of the day, including the railway fare and conveyance from Alton to 
Selborne and back, will not exceed five shillings a head. Addresses will be given 
during the day by influential persons acquainted with the neighbourhood, and 
parties will be conducted by archteologists, botanists and others. 
The Annual General Meeting will be held at the rooms of the Royal 
Society of British Artists, Suffolk Street, Pall Mall, .S.W., on Wednesday, 3rd 
May, at 8 o’clock. Speeches will be delivered by several distinguished members 
