VOL. VII.] DR. BUREAU ON THE PARTRIDGE. 169 



On the 75th day, when the new fifth primary has grown 

 20-25 mm., the second and ninth secondaries are lost. 



On the SOth day, when the new fifth primary has grown 

 to 45 mm., the tenth and sometimes the first secondary 

 is dropped, but more frequently the latter is retained until 

 after the loss of the fourth primary. About this time also 

 some young birds renew the scales of the feet. 



On the 84:th day, the new fifth primary being 64.5 mm. 

 long, the first indication of the callosity on the tarsus of males 

 may sometimes be felt. 



On the SQth day the fourth primary is shed, the new fifth 

 being 72.4 mm. long. The first, second, and third juvenile- 

 primaries are full-grown. The plumage is practically that 

 of the first-winter, except that the outermost row of flank- 

 feathers, certain of the scapulars, and the three or four inner- 

 most secondaries are still juvenile ones. The new outermost 

 pair of rectrices are about half-grown. The callosity in 

 the males is now visible. Length {^) 353-380 mm., ($) 

 320-325 mm. ; expanse {^) 540-545 mm. (?) 488-500 mm. ; 

 tail projects beyond wings 70 mm. Weight 295-415 grams. 

 While the fourth primary is growing, the remaining secondaries 

 are shed as follows : the eleventh on the 86th day, the 

 twelfth on the 95th, the thirteenth on the 100th, and the 

 fourteenth on the 105th, but the last-named may be retained 

 until after the loss of the third primary. 



On the 105th day the third primary is shed, the new 

 fourth being 85.2 mm. long. The plumage is entirely that 

 of the first-winter (except sometimes the innermost secondary), 

 many feathers still retaining their sheaths at their bases. 

 Tail, full-grown except the outermost pair of rectrices. Length 

 {^) 355-360 mm., ($) 325-347 mm.; expanse {(^) 530- 

 545 mm., ($) 510-516 mm. Weight 402-465 grams. 



On the 130th day the third primary is full-grown, the 

 bird is also full-grown, and the moult finished. 



The Moult or the Secondaries. 



As in the Common Partridge, this takes place in two groups, 

 an internal (3-15) and an external (1 and 2). The former 

 are moulted from without inwards, and the latter from 

 within outwards. The first to be shed (the third) is shed 

 synchronously with the eight primary (41st day), the 

 second about the 49th, and the first about the 86th day. 

 The dates at which the others are lost liave already been 

 indicated. 



