72 BRITISH BIRDS. 



horse-power, and it seems rather unnatural to expect a 

 bird's flight-mechanism to be capable of such analogous 

 expansion of power, since it would be the reverse of 

 economical to maintain a similar reserve of power. 



Consider mankind — there is scarcely 20 per cent, 

 difference between the " record " and the general average 

 speed in any foot race. 



G. Age of First Arrivals. 



With regard to the much debated question of whether 

 some of the adults of each species do or do not lead the 

 way as pioneers of the migrant waves, I can only say 

 that, with the exception of the Redstart and Wheatear, 

 every species sufficiently well represented to enable a 

 conclusion to be arrived at, appeared to have some adults 

 among the first batch of arrivals, and this was actually 

 proved by obtaining specimens in the majority of cases. 

 There may, perhaps, have been adult females among the 

 Redstarts and Wheatears, but their appearance was not 

 sufficiently distinctive to enable me to separate them 

 from the young birds. 



With so many individuals of other species migrating 

 from (probably) the same breeding areas, and bound in 

 the same direction, it seems rather natural to suppose 

 that young birds may not always consider it necessary 

 to have one of their own species as a guide, but may, on 

 the contrary, join up with birds of other species — a 

 supposition which is of course supported by the frequent 

 appearance of heterogeneous assemblages of species 

 during migration time. 



H. Habits. 

 Since space naturally precludes a separate description 

 of the habits of each species, I shall endeavour under 

 this heading to describe, in more or less general terms, 

 only such habits as the act of migrating seemed to have 

 imposed upon the birds passing through Port Said. 

 Firstly, there was the desire for seclusion on alighting, 



