GALLl 



296 



organ has been mainly drawn. The simplest^ form of the 

 syrinx is seen in the peacock (fig. 143), where the modification 

 of rings at the bifurcation is of the sHghtest. The last two 

 tracheal rings are partly fused behind. The accompanying 

 series of illustrations (figs. 143-147) show some of the princi- 

 pal forms of syrinx among the Alectoropodes, in which it will 



Fig. 145. — Steinx of Callipepla califor- 

 nica. Front View. (After Gaekod.) 



Fig. 146.- Syeinx of Same. Back 

 View. (After Gareod.) 



be noticed that intrinsic muscles are but occasionally present. 

 When present they do not descend to the bronchi, but cease 

 upon the trachea some way in front of the bifurcation. The 

 most remarkable modification of the intrinsic muscles is in 

 Callipepla calif ornica (figs. 145, 146), where the muscles 

 descend the trachea posteriorly, and are inserted on to the 

 bronchidesmus. This state of affairs is not unlike what is 

 found, and will be described (see below), in the condor. It is 

 uncertain whether these muscles may be not more accurately 



