THE SPRING MIGRATION OF BIRDS. 217 



and the spring advanced with astonishing rapidity. 

 On the 20th of April, the first day the temperature 

 rose above freezing-point for nearly six months, the 

 Barking Crow {Coruus americanus) made its appear- 

 ance. The Raven {Corvus corcix) had remained 

 throughout the winter. On the ist of May, some 

 Canada Geese {Branta. canadensis) were seen at the 

 edge of an open place in the river accompanied by 

 a flock of Mergansers and other Ducks. The 4th 

 brought the Robin {Tiirdus migratorius)^ and some 

 Sparrows, and on the 5 th the Wavies {Anser hyper - 

 boreus), which usually lag a few days in the rear of 

 the Canada Geese, commenced to wing their way 

 northwards, and in a couple of days were passing in 

 such numbers that flocks were rarely out of sight." 



The following table will give some slight idea 

 of the spring migration of birds, half a dozen 

 familiar species having been selected for the 

 purpose of showing the gradual northern move- 

 ment. (See p. 218.) 



The subject of spring migration can scarcely be 

 said to be exhausted until the probable route, and 

 the dates of at least half a dozen stations to denote 

 progress and duration, of every Palccarctic and 

 Nearctic species have been carefully recorded. In 

 the almost complete absence of such data the 

 present chapter can only be regarded as a frag- 

 ment ; but sufficient I hope has been shown to 

 denote the general characteristics of the Spring 

 Migration of Birds, and at least to excite the 

 reader's curiosity, and possibly stimulate him to 



