276 ANATID^. 



friend John Morgan, Esq. In this female the beak was 

 yellowish-brown ; the head and upper part of the neck a 

 mixture of green and brown ; the white ring below per- 

 fect ; the lower part of the neck and the breast chestnut 

 brown ; the upper surface of the body a mixture of ash 

 brown and dark brown ;* the under surface dull white. 

 When this bird was examined after death the sexual organs 

 were found to be diseased, as in the cases of the Hen 

 Pheasants referred to and figured in the second volume, 

 pages 329 and 330. In the Illustrations to his Fauna of 

 Scandinavia, M. Nilsson has given a coloured figure of a 

 Duck in this state of plumage, plate 163, which is called 

 a barren female, and in which the curled tail-feathers are 

 made very conspicuous. From the general similarity in 

 these females to the appearance assumed for a time by 

 healthy males in July, I am disposed to refer this seasonal 

 change in males to a temporary exhausted state of the 

 male generative organs, and their consequent diminished 

 constitutional influence on the plumage. 



The windpipe of the Mallard is about ten inches long, 

 the diameter of the tube is of equal size throughout ; the 

 bony labyrinth is large, the vignette indicates the form by 

 its outline, but represents a section of the lower part of the 

 tube of the trachea, the bony cavity, and the bronchial 

 tubes, as seen from behind, the enlargement in this, as in 

 most of the other species, being on the left side. The 

 object here intended is to show the course of the air from 

 each lobe of the lungs to the single portion of the tube of 

 the windpipe. The column of air on the right side in the 

 bird, and in the representation, goes direct from the right 

 lobe of the lungs to the tracheal tube ; but the column of 

 air on the left side, on passing through the bronchial tube, 

 is opposed by the descending edge, and being divided by 

 it, a portion is sent in circles round the inner surface of the 



