COLOUR IN BIRDS AND QUADRUPEDS. 229 



Weasel in the northern states, is brown during six months of the year, 

 and in winter becomes white, with the exception of the tip of its tail, 

 which is black. 



I was not aware, until this paper had been nearly written, that any 

 one had published an account of a particular examination of the Er- 

 mine during those periods when it is subject to change its colour. I 

 am indebted to my friend Professor Moultrie, for a reference to a pa- 

 ragraph in vol. II., p. 24, of Flemming's Philosophy of Zoology, where 

 the following remarks occur. 



- "The appearances, exhibited by a specimen now before us are more 

 satisfactory and convincing. It was shot on the 9th of May 1814, in 

 a garb intermediate between its summer and winter dress. In the 

 belly, and all Ihe under parts, the white colour had nearly disappeared, 

 in exchange for the primrose yellow, the ordinary tinge of these parts 

 in summer. The upper parts had not fully acquired their ordinary 

 summer colour, which is a deep yellowish brown. There were still 

 several white spots, and not a few with a tinge of yellow. Upon exa- 

 mining those white and yellow spots, not a trace of interspersed, new, 

 short, brown hair could be discovered. This would certainly not have 

 been the case if the change of colour is effected by a change of fur. 

 Besides, whilst some parts of the fur on the back had acquired the 

 proper colour, even in those parts, numerous hairs could be observed of 

 a wax yellow, and in all the intermediate stages, from yellowish brown, 

 through yellow, to white. 



"These observations leave little room to doubt that the change of 

 colour takes place in the old hair, and that the change from white to 

 brown passes through yellow. If this conclusion is not admitted, then 

 we must suppose that this animal casts its hair at least seven times in 

 the year. In spring it must produce primrose-yellow hair ; then hair 

 of a wax yellow; and lastly of a yellowish brown. The same process 

 must be gone through in autumn, only reversed, with the addition of 



winter, were seen around this retreat almost every day during autumn, till the ground became 

 covered with snow. They could now no longer be traced, till the snows began to melt, when 

 their holes were again opened, and they were seen as usual. Our Mustela vulgaris ought to 

 be carefully compared with that of Europe, which goes under the same name. 



