504 ON THE TRACHEA OF THE GALLINAE. 
posterior notching of the rings of the trachea is on the thin edges of 
the flattened tube. 
In conclusion, it may be asked what light this detail concerning 
the bifurcation of the trachea throws on the mutual affinities of the 
genera of the Gallinw. It is very infrequently that the study of a 
single organ justifies the formation of an ultimate classification of any 
group ; and the windpipe of the Galline is not peculiar in this respect. 
Several hints are to be derived from this investigation, however, not 
unimportant in my estimation. é 
Pavo seems to stand alone on account of the simplicity of its 
bronchial bifurcation. 
- There seems also to be a tendency for the majority of the Galline 
to fall into two divisions, a Coturnicine and a Phasianine; in the 
former of which it is the bronchial semirings which are most specalized, 
at the same time that the anterior extremities are pointed and pro- 
duced inwards. In the latter group it is the last tracheal ring that is 
most modified, its sides being always upturned. Upon this assump- 
tion it is not easy to place the genera Gallus, Lophophorus, Meleagris, 
and Numida. The others fall into the following order :— 
CorurRNICINE. PHASIANINZ. 
Caccabis. Euplocamus. 
Argus. Pucrasia. 
Polyplectron. Ceriornis. 
Ithaginis. Phasianus. 
Lophortyx. Thaumalea. 
Oreortyx. Orossoptilon. 
Arboricola. Lagopus. 
Rollulus. Tetrao. 
Ptilopachys. (Meleagris ?). 
Coturnia. Perdiz. 
It is surprising to see how much the lower end of the trachea of 
the adult Gallus differs from that of Phasianus and its allies. A study 
of the development of the windpipe of the Common Fowl—which I 
have not had the opportunity of undertaking—would probably throw 
considerable light upon the subject. 
a 
