81 



Mr. Tegetmeier laid before the members specimens illustrating 

 the differences produced in the hens of the Common Pheasant and 

 Domestic Fowl by disease or degeneration of the ovary. 



The late Mr. Yarrell noticed that disease of the ovary in the hen 

 Pheasant resulted in the assumption of the male plumage and voice. 

 Mr. Tegetmeier exhibited a specimen of a game hen, that had become 

 sterile from age, in which the plumage was completely changed to 

 that of the male. 



In cases of disease of the ovary in domestic hens, a different altera- 

 tion ensues. The plumage remains perfectly unchanged, but the 

 comb and wattles become extraordinarily developed, in many cases 

 even surpassing those of the male bird in size. The birds crow like 

 the males, and are popularly known as Hen-cocks. The alteration 

 had been observed as resulting from melanosis of the ovary from 

 cartilaginous degeneration, and from a generally diffused inflamma- 

 tion arising from the escape of an ovum from the oviduct. 



May 12, 1857. 



Dr. Gray, F.R.S., in the Chair. 



The following papers were read : — 



1. On Parus meridionalis and some other species men- 

 tioned in the Catalogue of Birds collected by M. 

 Salle in Southern Mexico. By Philip L. Sclater, 

 M.A., F.L.S., etc. 



In the'Catalogue of Salle's Mexican Collection, given in these Pro- 

 ceedings for last July, I described a new species of Titmouse under 

 the name of Parus meridionalis. Not having at that time within 

 my reach specimens of Parus atricapillus of the United States, it 

 was not without hesitation that I separated the Mexican species from 

 that bird. I am now, however, able to exhibit to the Society speci- 

 mens of Parus atricapillus which I obtained in North America last 

 autumn, and I think that a comparison of them with the type of my 

 Parus meridionalis (which M. Salle has again kindly placed in my 

 hands) leaves no doubt that these two Pari are, as I had anticipated, 

 really distinct, although closely allied species. In its upper plumage 

 Parus meridionalis differs from P. atricapillus in having the back 

 deeper cinereous without any tinge of brown — the narrow outer 

 edgings of the secondaries are brownish and not white, and the black 

 does not extend so far down the nape. Below, the plumage is also 

 much darker ; the whole abdomen and crissum being of a nearly uni- 



No. CCCXXXII. — Proceedings of the Zoological Society. 



