DR. BUREAU ON THE PARTRIDGE. 217 



the yellow transverse bars, first pointed out by Mr. 

 Ogilvie-Grant as being characteristic of the median wing- 

 coverts of females, but even these Dr. Bureau states are 

 sometimes present (at any rate in birds from Loire 

 Inferieure) in males after both their first and second 

 moults, but in these cases other indications of the male 

 sex are usually present. 



A second good distinction, although not so invariably 

 present as the first, consists of the yellow, drop-shaped 

 spots at the ends of the feathers of the back in females. 

 Their distribution is, however, variable, they may cover 

 either the whole back or its upper part only, and may 

 be absent. The third distinguishing character is the 

 well-known horse-shoe, but unless its variability is well 

 understood it is a very fallacious character, and should 

 in most cases only be used in conjunction with others. 

 The horse-shoe of the male seems to be almost constantly 

 a well-developed one, but that of the female exhibits 

 every variation between complete absence (when the 

 birds are often said to have a "white horse-shoe") 

 through more or less imperfect horse-shoes composed of 

 many or few oval chestnut spots, up to a complete horse- 

 shoe almost or quite as well developed as in the male. 

 Mr. Ogilvie-Grant states that in females after the first moult 

 a well-developed horse-shoe appears to be characteristic 

 of certain districts in England, and a feebly developed 

 one characteristic of others, while the former lose the 

 greater portion of it at their second moult. In Brittany, 

 on the other hand, Dr. Bureau finds that the variation 

 in development of the horse-shoe is entirely individual, 

 and bears no relation to age. Occasionally specimens 

 are met with in which the sex is not determinable with 

 certainty without an examination of the internal organs. 



In the foregoing we have summarized Dr. Bureau's 

 methods of working and the results that he has 

 achieved, in the part of his book that deals with moult 

 and the use to which it can be put in the determination 

 of a bird's age and sex, but space forbids us to reproduce 

 any of the numerous examples, plates, and diagrams that 

 he makes use of to illustrate each step of the work. It 

 must suffice to say that these appear amply to bear out 



