2o6 THE AUG RATI ON OF BIRDS. 



yet travel by day in autumn, as for instance the 

 Quail {Coturnix communis)-, whilst others journey 

 by day in spring and by night in autumn, as for 

 instance the Common Bee-eater {Merops apiaster) ; 

 others yet again always by day or by night, or by 

 day and night at both seasons. The reason for 

 this change according to season remains a mystery, 

 and the practice may be found to prevail more 

 extensively when Migration becomes better known. 

 The general direction of Spring Migration, as 

 previously remarked, is broadly speaking from 

 south to north, yet there is a considerable amount 

 in other directions. Some of these what we may 

 call minor streams of migration are intensely inter- 

 esting, not only in themselves, but as showing how 

 certain species have increased their areas of dis- 

 tribution in summer in a longitudinal rather than 

 in a latitudinal direction. Hence we not only find 

 migration from east to west in spring, but from 

 south-east to north-west, as well as the almost 

 universal stream from south to north. The Rose- 

 coloured Pastor {Pastor roseus) winters in India, 

 and migrates to South Siberia, Turkestan, the 

 Caucasus, South Russia, and as far west as Italy, 

 to breed. Canon Tristram observed incredible 

 numbers of this species on migration in spring, 

 crossing the plains of Syria in the Orontes Valley. 

 For three days during the last week in May flocks 

 continued to pass one after the other all flying due 

 west towards Europe. The birds made consider- 

 able noise as they flew along, chattering to each 



