iv INTRODUCTION. 



the base of the feather. In certain cases two or more of 

 these modes, by which a seasonal alteration is effected, 

 take place in the same individual. In some birds, 

 which assume a partially black colour, at the spring 

 moult, so great is the energy of the system in this coloration, 

 that even old feathers about to be shed are sometimes 

 coloured black. In all these cases the ordinary or winter 

 plumage is re-assumed at the autumn moult ; and in 

 some of these cases where the change takes place in the 

 feather itself without a renewal, the summer colour is 

 re-absorbed wholly or partially before the moult. This 

 absorption of color is also observed in some of the addi- 

 tional tufts put forth at the spring moult, which some- 

 times change to the winter colour before they have had 

 time to drop off, as I have observed in the ear-tufts of the 

 Lesser Florikin, Otis aurita. In a few cases a spring 

 moult takes place, which is not accompanied by any change 

 of colour except such as is due to a freslier plumage. 



Some birds retain their entire nestling plumage till the 

 second autumn. Others renew every feather at the first 

 or autumn moult ; and others change their nestlino; clothing 

 plumage only, the first autumn, retaining their nestling 

 primaries till the second autumn; and in no case are the 

 primary quill feathers ever shed except in the autumn 

 moult. 



In many birds the female differs from the male by having 

 a less bright plumage, or a different shade of colour; and 

 in these the young birds generally resemble the female. 

 In those exceptional cases where the female is the brighter 

 coloured of the two, the young resemble the male bird. 

 When the adult male and female are alike in plumage, the 

 young, in some cases, resemble the parents, in others have 

 a peculiar livery. 



