APPENDAGES TO THE HEAD. 253 



head. The most striking instance of this is seen in 

 the elephant ; but it is no less remarkable in the ant- 

 eaters, the shrews, and the mice ; while the common 

 term of " pig-eyed," proverbially applied to small- 

 eyed people *, expresses the singular fact we are now 

 illustrating. The whole family of humming birds 

 have the longest bills, and the smallest eyes, in pro- 

 portion to their size, of any birds yet discovered ; 

 and these latter organs are placed so far from the 

 naked part of the bill, that they seem central be- 

 tween the nostrils and the nape. When, therefore, 

 any such particular structure can be traced through 

 animals of different genera, and even in totally dif- 

 ferent classes, we feel assured that it must exercise 

 an important influence in the system of nature, and 

 that especial regard must be paid to such circum- 

 stances, in characterising natural groups. Similar 

 results would attend an investigation of all such 

 animals as have, in opposition to the last, very short 

 and thick muzzles. Appendages to the head, 

 whether in the shape of horns, crests, protuberances, 

 or wattles, may be considered as furnishing strong 

 and highly valuable characters of primary import. 

 Horns are one of the chief characteristics of the 

 ruminating order of quadrupeds — Ruminantia — in 

 which is comprised not only the family of oxen, but 

 the deer and antelope races. In these, the horned 

 structure is at its maximum of developement, and 

 consequently assumes the rank of an essential 

 character. In the PachydermatcB, or thick-skinned 

 quadrupeds, belonging to the same order, we have a 



* It is very singular that " pig-eyed " people have very 

 generally a long, but never an aquiline nose. • 



