Explanation of Plate.
| Fig. 1. | Fratercula arctica, adult male, in spring, or during the breeding season (natural size). Coast of Brittany, 6th June, 1876. (Coll. Dr. Bureau.) |
| Fig. 2. | Fratercula arctica, adult male, in winter or after the breeding season (natural size). Cape Ferret, near Arcachon, Gironde, 4th March, 1873. (Coll. Dr. Marmottan.) |
| Fig. 3. | Fratercula arctica, undergoing the moult (enlarged to twice the natural size). |
| Fig. 4. | Fratercula arctica. Adult assuming the nuptial appendages. |
| Fig. 5. | Horny pieces which fall off after the breeding season. |
BIRD MIGRATION IN THE SPRING OF 1878.
By John Cordeaux.
The following notes, although perhaps not containing anything of special importance, will be interesting to British ornithologists, showing as they do the almost continual stream of migrants which passed Heligoland for many weeks in succession during the spring of the year. They were sent to me from time to time by that indefatigable observer, Mr. Gätke, and are taken from his own notes and observations.
The autumn migration of birds southwards in 1877 was greatly prolonged beyond the usual period; and from Mr. Gätke's notes it appears that, even as late as the commencement of February, all the birds had not left the North of Europe, many laggards remaining after the usual period of migration. This abnormal state of affaire was probably induced by the extremely mild winter of 1877–78 in Scandinavia. Food continuing accessible, and the weather being not too severe, some of the more hardy species seem to have delayed their journey southward until the early part of 1878, when the sudden outburst of severe weather towards the end of January sent the loiterers southward with a rush. It will be seen that scarcely had the down-stream ceased, before the return flood set in, and continued, with but slight intermissions of unfavourable
