INTRODUCTION. 



XXV11 



Prom the foregoing review of the dispersion of the various species of the Hornbills it will 

 be perceived that the Buceeotid^: are pretty equally divided at the present day between the 

 Ethiopian and Oriental Regions, the first having twenty-seven and the latter twenty-nine species, 

 while but a few, apparently the remaining representatives of a numerous race, are scattered 

 about the islands of the Malay archipelago. Wallace has so thoroughly exhibited the probable 

 way in which the great Australian continent has been broken up and left in the condition we 

 now see it, and, at a similar period, how the Asiatic continent extended its limit until it 

 almost reached its great southern neighbour, that it will be quite unnecessary to discuss the 

 subject here; but unquestionably, during the convulsions of earth and sea, with the rising and 

 falling land, the Bttcerotid^e, like many other great families of birds, have become widely 

 scattered from the original continent which was once their home. Species have become separated 

 from each other ; some that may have been local in their habitat have disappeared altogether, or 

 else are found today inhabiting one island only, such as those now living upon Celebes, Java, 

 and certain of the Philippine Islands ; while others that were widely dispersed over the old 

 continent are now met with in many of the islands of the archipelago. In both the Oriental 

 and Ethiopian Regions the range of many species appears arbitrarily drawn, and is inexplicable 

 to us ; but our difficulty may arise, in a measure at least, on the African continent, from our 

 lack of knowledge of the fauna of the interior of that great land ; for many of the species we 

 now regard as restricted in their habitat may in reality have a wide dispersion. The same 

 remark will apply to certain divisions of the Oriental Region ; for we know nothing of the extent 

 of range or number of species of this family beyond the north-eastern portion of the Indian 

 subregion. How many may inhabit the unknown forests stretching away to the northward, or 

 how far these birds may penetrate into the Palsearctic Region, or even to what degree, if at all, 

 the family may be represented there, has not yet been ascertained. We can only rely upon 

 future research for a solution of the problem. At present our knowledge simply points out to 

 us that the " geographical distribution of the Hornbills seems quite in accordance with the 

 almost universal belief of modern naturalists, that the present position of every living thing 

 upon the earth is the result of that long and complicated series of geological changes and 

 organic modifications which the globe has ever been and still is undergoing." 



The following list gives, in a condensed form, the geographical distribution of the genera 

 and species of the BucerotidtE : — 



1. Bucorvus. 



Bange of the Genus. 

 Ethiopian Region. 



Bange of the Species. 



1. Bucorvus ahyssinicus. East Africa : Abyssinia and Sennaar. 



2. Bucorvus pyrrhops. Gaboon. 



3. Bucorvus cafer. Angola ; Damaraland ; Caffraria. 



