64 Proceedings of the Royal Society of Victoria. 



time when the moult of brown is strong. As described later, one 

 bird shews the acquisition of both " blues " and " browns " in 

 March, as if a war was being carried on for the mastery. I con- 

 sider the " browns " would have gained, though this skin still 

 remains an oddity. The change of bill from brown to black 

 appears to be a spring move, and according to the large number 

 of moulting birds in March — April, the act evidently is confined 

 to birds at least 15 months old, judging by the color of bills. 



Adult males represented with their " blues " become scarce by 

 early April, nevertheless they are easily detected while brown as 

 leaders of families. 



During the winter months it is not unusual to count ten — 

 twelve birds, of which only one is in livery, or a group of five 

 (Af. goiddii) to six {M. cyaneus) ordinary brown birds foraging 

 along a creek bank ; but it is quite apart from the ordinary to 

 count twenty-seven sombre colored birds I^M. cyaneus)., in one 

 brake of thicket, with a possible three or four more. In June, 

 1897, I was favored with a sight of this large group of what our 

 boys call the " blue-tit," when the leader flew away with nine- 

 teen as immediate followers in single file, and the remainder, 

 feeling themselves disbanded, with very little hesitation, followed 

 in pursuit of the first contingent. There were no blue birds ! If 

 there are no " blues " in a flock of twenty-seven would there be 

 any in a district association of one hundred % This was the 

 question I set Mr. Graham to unravel — which was answered 

 satisfactorily. In the 1897 winter a thorough search was made 

 through a portion of Heytesbury, with the result that 1 adult 

 male in 100 brown birds could not easily be found. In 1898 

 this was modified to 1 — 100 birds. The ratio stands also for 

 1st April of this year. From this I conclude, as far as 

 M. gouldii is concerned, that the bird which obtains its " blues " 

 in autumn is in the ratio of 1 to 100 brown males and females, 

 and 1 to 20 in males that don the " blues " in spring. If the 

 nuptial plumage is put on during the late autumn, it is doubt- 

 less retained throughout the winter on to early in January, 

 when precocious birds moult their blues as is shown in one skin 

 in my cabinet. 



With regard to the time necessary to a moult of " blues," 

 Mr. Graham gave liis most careful attention in set parts of each 



