Geographical Distribution 349 



migration, too, a carefully prepared series of statistics will 

 be necessary, before one can hope to generalize, and years 

 must elapse before it will be possible to obtain these 

 statistics. It must, therefore, be understood that only a 

 general idea of the geographical distribution of birds is 

 put forward in the present chapter. It is merely a guide 

 to the final study that a zoologist undertakes, after he has 

 mastered the details and the literature of the various species 

 of birds. 



The importance of interesting himself in the distribution 

 of a species should be impressed on the beginner from the 

 first. I suppose that all ornithologists commence much in 

 the same way, by collecting birds' eggs ; and indeed a 

 properly formed collection of the latter, with each egg 

 bearing its own history on the shell, is very instructive ; but 

 it must always be remembered that every egg in a boy's 

 collection should be, like Caesar's wife, "above suspicion," 

 and that he should know for certain every detail connected 

 with the finding of each nest, while he must also be sure 

 of the identity of the birds which laid the eggs. It 

 would astonish some of the boys of to-day, if they could 

 see the collecting-diaries kept by some of our greatest 

 living ornithologists when they were young. No point was 

 considered too unimportant for record, and it is this precise 

 method of noting facts which has distinguished their career 

 in after-life, and has been the means of giving us the 

 splendid series of observations on birds which are such a 

 credit to British science. I have already alluded (p. 325) 

 to the band of workers to whom in this country we owe so 

 much, and I would only here emphasize the necessity for 

 every young beginner to follow the method of work in- 

 culcated by these great ornithologists. The same care 

 must be shown in collecting the skins of birds. Too much 

 pains cannot be taken with the preparation of the skins, 

 and here science owes a great debt to American zoologists, 



