no THE BIRDS OF HELIGOLAND 



more northern latitudes. Some of these latter, however, arrive so 

 late in the southern area, that the old birds which have hitherto 

 tarried there will have begun to depart at the time when the 

 migration of the young individuals from the north is about to 

 terminate. Hence it results, in these southern latitudes, that old 

 and young birds, having no relation of kinship with each other, are 

 nevertheless seen to migrate at the same time. Last of all, forming 

 the rear-guard of the migration of the particular area, there will 

 pass the old birds whose breeding haunts are in the extreme north, 

 individuals whose late appearance Naumann endeavoured to explain 

 by assuming that they had been detained by accidents or mishaps 

 of various kinds. 



Hence the course of the spring migration, as detailed above, 

 actually supplies proofs, such as one might logically expect to 

 follow from what we have stated, in regard to the order in which 

 the autumn migration of birds proceeds, because — in the spring, 

 in the case of all species, the most handsome old birds are 

 invariably the first to hasten back to the old homes, as the heralds 

 of reawakening life ; these are soon joined by old females, whose 

 numbers increase, while those of the males decline, and the 

 migration is brought to a close by the younger birds. 



There follows, howevei', in the wake of the main body of 

 migrants, an ii-regular rear-guard of weaklings and crippled indi- 

 viduals, some with the toes of one foot wanting, others with the 

 whole foot lost up to the joint, a rounded ball, with more or less 

 hardened sole, being developed in its place. Others, agam, have 

 lost a portion of their flight-feathers or of the rectrices. 



If among such a rear-guard of Thrushes, a fowler or collector 

 happens to find an apparently very handsome male Blackbird, in 

 glossy plumage and brilliant orange-yellow bill, or a King Ousel, 

 with a very white breastband, he will regularly, on capturing 

 such a speciinen, find proved what he was, in fact, convinced of 

 before, viz. that the bird has either lost from six to nine of its 

 rectrices, which have only been restored to half their length, or 

 that the wings have suffered damage of a similar kind, which 

 has not yet been completely repaired. 



Some Hooded Crows are seen occasionally in a truly pitiable 

 condition, labouring, with scarcely half their wings left, to follow 

 their companions, who have preceded them by as much as several 

 weeks. It is singular how such a bird could lose so many of the 

 flight-feathers of both wings, and sometimes indeed quite unin- 

 telligible how it can still continue to fly with the few it has left. 



How hard an effort this is is clearly shown by the increased 

 number of the strokes of its wings; notwithstanding, it slowly 



