THE TROGONS, 309 



of the great researches which have been made in this depart- 

 ment of natural history. In the time of Linnaeus, who enu- 

 merates only three species, the existence of these birds in 

 India and Africa was not known. Levaillant added the 

 Narina ; and of late years, Vieillot, Spix, Temminck, and 

 Swainson, have each contributed to enlarge the catalogue. 



