130 



each species as against one young bird of the last-named only. 

 Again, almost all the examples of the Rose-coloured Starling 

 which have occurred are old birds, and so on. 



Considering the relative situations of the breeding grounds 

 and winter quarters of these species, this is just what might have 

 been expected. The general direction of their migratory flight 

 in spring being south-east to north-west, and, of course, the 

 reverse in autumn, how could it be expected under these cir- 

 cumstances, that young birds should migrate in an exactly oppo- 

 site direction to their parents ? The improbability of the latter 

 fact seems to have occurred to Herr Gatke, for, writing on the 

 Short-toed lark (p. 357), he remarks : " In the absence of any 

 single actual instance in support of it, the idea of an autumn 

 migration directed to the north-west from Greece or Asia Minor 

 cannot be entertained." He further adds in alluding to these 

 exceptional visitors : "No more do the conditions under which 

 such migrants make their appearance admit of the conclusion 

 that these movements are merely of a roving or blundering kind, 

 without definite plan or aim." It is difficult, however, to see to 

 what else but blundering we are to attribute the presence of the 

 few young birds of these south-eastern species, which have been 

 captured so far from the home in which they were reared. It is 

 simply impossible to prove an intention on their part to under- 

 take a journey in an exactly opposite direction to that of the vast 

 majority of their fellow-travellers. Why should it be assumed 

 from the fact of eastern and north-eastern species occurring in 

 autumn and those from the south and south-east in spring, that 

 these casual visits are dependent on definite laws or causes of a 

 recurring kind. The very lines of flight are sufficient explana- 

 tions in themselves. It would, of course, be absurd to expect 

 the appearance of young from the latter quarter in spring, or in 

 other words, before they are hatched. 



In the idea of Prof. Newton, if we grant the existence of laws 

 determining the flight of every winged vagabond they must be 

 very different from those which are obeyed by birds commonly 

 called migratory. The former laws would seem to be controlled 

 by purely external circumstances, and while we may predict with 

 a reasonable degree of certainty the occurrence of a certain 



