author's abstract of this paper issued 

 by the bibliographic service, september 16 



STUDIES OF NORMAL MOULT AND OF ARTIFICALLY 



INDUCED REGENERATION OF PELAGE IN 



PEROMYSCUS 



H. H. COLLINS 



Scripps Institution, La Jolla, California 



FIFTEEN FIGURES 



CONTENTS 



1 . Introduction .' 73 



2. The postjuvenal moult 76 



3. Later moults 81 



4. Regeneration of pelage in juvenal mice 81 



5. Regeneration of adult pelages 86 



6. Discussion 88 



7. Summary 94 



1. INTRODUCTION 



It is a matter of common knowledge among naturalists that 

 many birds and mammals undergo more or less marked "changes 

 in appearance as the result of moult. These moults may mark 

 different stages in the life cycle of the individual or they may be 

 seasonal in character. 



In general the greatest changes in appearance are incidental 

 to the transition from the juvenal to the adult. Especially 

 among birds, there are many species in which the differences are 

 quite striking. 



To quote Allen ('94a) in regard to Passerine birds : 



This 'first' or 'nestling' plumage can usually be recognized by its 

 loose, fluffy texture, as compared with that of adult birds of the same 

 species, even though the coloration may be similar; but generally it 

 differs notably also in color, and often in pattern of markings, from 

 that which immediately succeeds it, or from any plumage which maj^ 

 be afterward acquired. Familiar illustrations are furnished by the 

 robin and the bluebird, where the first plumage is so strikingly unlike, 

 both in color and markings, that of the adult bird of either sex (p. 92). 



73 



