The Sky-lark is perhaps even more interesting in its autumnal invasion of the coasts of the northern shires. Every autumn, especially towards the end of October or early in November, incredible numbers of Sky-larks cross the German Ocean both by day and by night, and land in the district of the Wash, to name but one locality, although similar phenomena may be witnessed here and there from one end of our eastern coast-line to the other, from September onwards. Year after year have we seen this autumn invasion of the Sky-lark. Day and night the migration continues, the birds coming in from the sea in flocks and smaller parties, flying at a moderate height, say from thirty to fifty yards above the earth, and in a by no means hurried manner. We have repeatedly noticed a few birds commence to warble the moment they left the sea and reached the land. Many thousands of these birds continue their way south along the coast, doubtless in some cases to follow the rivers inland; others fly inland over the fields, continuing the exact direction of the course followed over the sea. In the same district the autumnal passage of the Hooded Crow is little if any less impressive. This migration usually commences about the middle of October, and lasts about a month. The arrival of this bird in the Wash district is almost regarded with as much interest as the appearance of the Swallow in spring. Fishermen and farmers in the locality say that the two birds are never seen in the air together, meaning by this that the Swallow has gone to the south before the Crow comes in from the east. Unlike the two other species we have just alluded to, the Hooded Crow migrates exclusively by day--at least that is our invariable experience. During the periods of its passage the bird may be remarked coming towards the land from the sea in parties, in twos and threes, and now and then in a large open flock, flying at a moderate height and in a somewhat slow and deliberate manner. Hundreds of thousands of this species must enter the British Islands by way of the Wash alone. Many of these do not penetrate inland far, but live during the ensuing winter on the farms and saltings; others, however, follow the river-valleys to more central areas. It is interesting to remark, however, that the Hooded Crow does not migrate down the Humber and the Don valley to South Yorkshire, where at all seasons it must be regarded as a rare bird.