102 MR. R. F. TOMES ON THE GENUS VAMPYRUS. [MaV. 26 



March 26th, 1861. 



Dr. J. E. Gray, V.P., in the Chair, 



Mr. Tegetmeier brought before the Meeting Uving specimens illus- 

 trating an undescribed abnormal variation of plumage in the Gallus 

 domesticus. 



The alterations previously noticed vFere the assumption of the male 

 plumage by the females. These changes, which are dependent on 

 diseased or abortive ovaries, were described by Mr. Yarrell in the 

 ' Philosophical Transactions' for 1827. 



The specimen brought before the meeting illustrated the assump- 

 tion of the female plumage by the adult male. A cock, of the va- 

 riety known as the Brown-breasted Red Game, was hatched in the 

 spring of 1859, and assumed the perfect male plumage in the autumn 

 of that year; in the autumnal moult of 1860 it shed the male plu- 

 mage and became perfectly hen-feathered, not only as to the colour 

 of the plumage, but also in the form of the feathers. This remark- 

 able variation was attended by a slight increase in size and muscular 

 development ; the spurs were well-grown and remarkably sharp, the 

 crow remained unchanged, and the bird retained its procreative 

 power, with an increased amount of combativeness. 



The alteration was stated to be not unknown to those who breed 

 game fowls for the purpose of cock-fighting, the birds being termed 

 " hen-cocks," and remarkable for their courage and endurance in the 

 cock-pit. The engraved portrait of a celebrated victor was exhibited. 

 Mr. Tegetmeier stated that he was not aware how far the disposi- 

 tion to undergo this change was hereditary, but that he was putting 

 it to the test of experiment. A young cock hatched in 1860 from 

 the hen-feathered male before it had undergone the change, was 

 shown in perfect masculine plumage. 



In the Sebright or Laced Bantams (a variety originating with Sir 

 John Sebright, whose mode of producing it was never published) 

 the males are hen-feathered, but the condition is congenital ; whereas 

 in the bird exhibited the change took place in the second year, and 

 the circumstances that determined the alteration were altogether 

 unknown. 



The following papers were read :— 



1. Observations on the Genus Vampyrus, and its Allies. 

 By Robert F. Tomes, Corr. Memb. 



(Plate XVIII.) 



Amongst the numerous species of Chiroptera which passed under 

 notice when preparing the various papers which have appeared in the 

 ' Proceedings ' of this Society, was one which, from its considerable 



