Vol. x\ix.] 62 



the male dress was due to tlie sexual organs having been 

 injured or diseased. 



In the case of the males, all those in so-called female 

 plumage had their sexual organs healthy. Some other 

 cause, therefore, must be sought for the assumption of this 

 curious plumage. He suggested that it was probably due 

 to an interference in the pigment while it was being deposited ; 

 and if that were the case, why should such plumages be 

 referred to as female plumage ? So far as his examination 

 of specimens had gone, the abnormal feathers in these 

 birds were not exactly like those of the female, and he 

 suggested that they might be produced simply by a change in 

 the normal deposition of the pigment. The fact that parts 

 of the tail-feathers of the specimens shown were normal 

 and parts were abnormal seemed to show this, as also did 

 the fact that in some cases the normal plumage had been 

 regained at a subsequent moult. If the male were to assume 

 the plumage of the female, surely such an assumption should 

 be due to a derangement in the sexual organs. 



In the case of Pheasants probably many more males were 

 wounded than females, yet such abnormal plumage in the 

 male was extremely rare, while in the female it was quite 

 common. 



Mr. W. P. Pycraft remarked that the evidence seemed 

 to show that the partial assumption of female plumage by 

 males was due to a lack of ^'tone'^ or vitality at the time 

 of moulting. This was indicated in the tail-feathers, for 

 example, where the distal portions of the long middle 

 feathers commonly resembled those of the female, while the 

 rest of the feather was normal. Occasionally the process was 

 reversed. In one of the birds shown at the last Meeting he 

 pointed out that the feathers developed at the beginning of 

 the moult showed markings characteristic of the female — 

 the tail showing the coloration of both sexes, — while the 

 feathers still in sheath all displayed the coloration charac- 

 teristic of the male. 



