elevated as is represented in the older portraits of singing 
birds. As the voice is not modified in the mouth, birds are 
able to sing with their bills full of insects. 
In the Golden-eye Duck the trachea of the female is de¬ 
void of peculiarity, and the syrinx is simple and provided 
with one pair of muscles. In the male there is a large irreg¬ 
ular fusiform swelling at the junction of the lower and 
middle third of the trachea made up of the enlarged tra¬ 
cheal rings. At the lower end, where the trachea splits 
into the two bronchi, there is a still larger swelling, vari¬ 
ously known as the labyrinth, tracheal tympanum, or bulba 
ossea. This latter modification is found in the Mergansers 
and in many, but not all, fresh-water and diving ducks. It 
is believed to be a reverberatory chamber to increase the 
volume of sound, and, as it is only developed in the male, 
it is in the nature of a secondary sexual organ. Pycraft 
pertinently says: “It is curious that in the Mallard, for 
example, the males have but a low hoarse note, while the 
call of the female—which lacks this resonating chamber, if 
such it is—is loud.” 
With both a labyrinth and an enlargement of the trachea 
one would suppose that the male Golden-eye* would have a 
remarkable voice, but such does not seem to be the case, 
unless sounds are made that are inaudible to human ears. 
Although the Golden-eye is a familiar duck,, few ornithol¬ 
ogists have heard it emit any vocal sounds. Wilson, who 
describes accurately both the upper swelling of the trachea 
and the labyrinth in the male, makes no mention of any 
voice. Audubon makes no mention of any voice. Cones is 
silent on the subject, as are also Forbush and Rich. 
Nuttall says: “Although furnished with a remarkably 
complicated trachea in the male, and the name of Clangula. 
we cannot learn that they ever possess any audible voice.” 
Baird, Brewer and Ridgeway say: “Although generally a 
very silent bird, yet, just before it leaves for its breeding- 
places in the spring, the male has a rough croaking note; 
and this note may also be heard if, having fallen wounded 
to the ground, it is taken alive.” 
* Barrow’s Golden-eye has a much smaller enlargement of the trachea, 
but its notes have not been described. Allan Brooks, who has described 
the courtship, does not mention any voice. 
7 
