ascertaining the number of old birds, and afterwards carefully examining as many nests as possible, I have obtained the following results:—
Number of birds in colony, fourteen. Number of nests, seven (each with sitting bird on June 11th).
1st nest was built on the top of a Sparrow's nest, and contained two incubated eggs, while the remains of a third egg were lying on the ground below.
2nd nest.—Three eggs slightly incubated.
3rd nest.—Three eggs of a very elongated type about half-incubated.
4th nest.—Three eggs much incubated.
5th nest.—Two newly hatched young, and one egg chipping.
The 6th and 7th nests were inaccessible, but a bird was sitting in each.
After carefully marking the eggs from nests 2, 3, and 4, I found that it was quite easy to sort out the clutches without making use of the marks.
Now, even supposing that the hens in nests 6 and 7 were sitting hard on empty nests, and had deposited their two eggs in two other nests (a most improbable supposition), there still remain fifteen eggs as the produce of seven hens; so that at least one hen must have laid three eggs.
May we not reasonably infer that the Swift not infrequently lays three eggs, as its alpine relative (Cypselus melba) is known to do?
The nests which I have examined consisted of a mass of feathers, a few straws, bud-cases, and blossoms from trees, fastened together with shining glutinous matter into a saucer or shallow cup. In one case this cup was built on to the top of a Sparrow's nest, and another was placed by the side of a Sparrow's nest containing young.
Young Swifts are extraordinarily unlike their parents, but, as they have already been described by White of Selborne and others, it is hardly necessary to do so here. One striking characteristic, which is very noticeable in the embryo, is the large proportionate size of the tibia as compared with the adult. The tarsus and claws are also well developed, while the featherless wings seem very small in proportion to the body. As far as
