10 
NATURE NOTES. 
the action having been kept up for successive generations 
becomes fixed and hereditary. And any feature thus per- 
manently retained becomes a “ specific character.” Thus new 
species arise as seeds get dispersed over new areas, and so 
brought under the influence of new conditions and a new en- 
vironment. 
George Henslow. 
1890. 
THE ORLETON SWIFTS. 
(a letter to the right honble. the earl of selborne.) 
The Vicarage, Orleton, Herefordshire. 
August 19, 
fiEAR LORD SELBORNE, 
Of all the birds in this quiet country place the 
Swifts have been the favorite objects of my attention 
for many years. The following notes are the result of 
observations for which I have had exceptionally good oppor- 
tunities. This house (the Vicarage) stands but a few yards 
from the church. A pathway without a fence separates the 
garden from the churchyard. About 70 or 80 Swifts build in 
the church, and I have watched them for wellnigh 20 years. 
But before you attend further to me I must ask you to read 
Gilbert White’s “ Monograph on the Swift,” in The Natural 
History of Selborne.''- This you will find no penance, though you 
may often have read it before. I shall ask you to take these 
notes as supplemental to his paper, for I shall not travel over the 
same ground, except there and here, just to corroborate or correct 
some of his conclusions or conjectures. 
The Swifts arrive here on or about the 5th day of May. 
One pair, or sometimes two, will appear first, a day or two after- 
wards half-a-dozen more, and within a week the main body will 
have come. And then when the sun shines the delightful scream 
will be heard, the most joyous of all Nature’s sounds to my ear, 
the sure prelude of Summer. 
The birds gather in a close-ordered company, and dash 
round in a ring between the Church and the Vicarage, chasing 
their shadows along the broad, tiled roof of the 
or 
following 
nave, as they skim over almost touching it with quivering wing- 
tips, screaming with all their might in an ecstacy of joy. To 
those who can enter into the spirit of it, the sound is a joyous 
one indeed. Their flight when in this chorus is peculiar. 
When they first join it their wings are spread straight out and 
held motionless, so that they start slowly and seem to give 
others time to join in ; but when they want to increase the 
* Letter 21, page 179, Original Edition. 
