BRITISH BIRDS. 81 



every species of birds of the country. It is clear that these stories, divested 

 of the incrustations of time, had a residuum of truth ; Sinbad's voyages 

 clearly so, like our nursery songs, as I have shown in the " four and twenty 

 Blackbirds baked in a pie." The speaking bird was simply a call-bird, which 

 is nothing very curious to us, to them strange enough. 



Migrants follow each other in a stream — that is to say, those which flock 

 for safety and guidance, which Warblers do not, as a rule. If a person stand 

 a few hours early in the morning in the autumn watching their departure, 

 perhaps a Swallow will pass, in two or more minutes another after him, and 

 so on ; but they all go the same road, as clearly as we should do wdth hedges 

 and guide-posts. I mean, if you have a group of trees on one side, and a 

 house on the other, if the line of migration travels between these two, all the 

 birds will keep to it in a way which is perfectly astonishing. This I have 

 often seen. Let us now suppose a young Nightingale, whose food is 

 abundant, to be urged by migratory impulse to go where he has never been 

 before, about July 7, by himself; for the old birds have not yet moulted, and 

 are not ready to start till the middle of August! He feels restless ; he cannot 

 go north ; why ? because the same reason prevents him which regulated his 

 father and mother. The conditions of life are not suitable. Nightingales 

 cannot go north beyond a certain point, because the conditions of life are not 

 suitable. It is vain to ask what are these ? what is meant by the expression ? 

 Every thing in which is the breath of life, nay more, every plant, I may almost 

 say every living thing acts in the same vt?ay as this Nightingale under discussion. 

 It knows by many indications if the conditions of life are to be found in the 

 place where it happens to be. If they are not, the plant, as it cannot move, 

 dies ; the bird goes away. If he starts north, finding matters worse, he 

 turns. We have now shut him out of the north, and w^e will suppose that 

 our young bird sets off to the east. He is brought up by the sea ; following 

 the coast-line he travels south, till the wind being suitable permits him to 

 cross. But imagine a bird to turn west and to proceed towards Wales, what 

 then ? It is not brought up by the sea, because it never reaches it ; but it is 



