24 CASSOWARIES OF NEW GUINEA. [CH. I 



G. Beccarii, Wokan. 



C. biearwnculatus, Aru. 



G. Bennetti, New Britain. 



G. laglaizei 1 , } T , . 



C. occipitalis,) 

 This case is analogous in many ways* to that of the 

 goats already dealt with. Isolation has led to the 

 differentiation of species from a presumably identical 

 stock. Furthermore, where the area is large it has proved 

 capable of sustaining several species, which is not the case 

 with those islands of limited extent, such as Ceram, which 

 harbour cassowaries. With this fact may be compared 

 the presence of only a single species of Ibex in the com- 

 paratively small tract of country occupied by the 

 Pyrenees, and the presence of this species in the more 

 extensive Caucasus. The existence of five out of the ten 

 species in New Guinea marks this large island out as the 

 head-quarters of the group from whence they have 

 migrated elsewhere, or perhaps, if the islands are to be 

 regarded as a broken continent, have been isolated. 

 That New Guinea is to be regarded as the original home 

 of the cassowaries is perhaps also shown by the fact that 

 the species now existing there present in themselves most 

 of the important modifications of structure which the 

 genus exhibits. In his most recent revision of the 

 cassowaries Mr Sclater divides those without wattles 

 from those which have these appendages. Both kinds 

 occur in New Guinea. On the other hand this con- 



1 The editor of the Ibis (Oct. 1894, p. 560) is inclined to doubt the 

 distinctness of these two species. 



