the merry -thought, or forked bone, and have been named 

 in consequence furculo-tracheal ; but this division does not 

 appear to afford any additional powers of voice. In figures 

 1 and 2, letters a a refer to the tube ; b b to the point of 

 division, or bone of divarication ; c to the bronchia, and d 

 to the elongated muscles going off to be attached to the 

 sternum. Another example of two pair of muscles at the 

 inferior larynx is found in the family of the Pigeons, as 

 represented in the third figure of this third group. The 

 second pair in this instance, marked e, are formed of a por- 

 tion of the sterno-tracheal muscles, but taking a different 

 direction. They proceed by a narrow slip, from that point 

 upon the tube where the first pair of muscles go off to be 

 inserted upon the sternum down the side of the trachea, to 

 be attached externally to the membrane between the lowest 

 ring of the tube, and the first ring of the bronchia, as shown 

 in the side view before referred to. By their contraction 

 they shorten the flexible portion of the tube between their 

 points of attachment, and produce tension upon the mem- 

 brana tympaniformis. 



