596 THE AMERICAN NATURALIST.  [Vor. XXXIV. 
was met by a strong antarctic element, coming from the supposed 
antarctic continent. The latter may be traced up to New Guinea 
and is probably older than the other antarctic element that enters 
Australia from the south. 
The Polynesian fauna, that of the eastern, oceanic part, has derived 
its population from two sources. The first way was from the Moluc- 
cas or the Philippine Islands through the Pelews and Carolines to 
the Marshalls, and thence down along the chain of archipelagoes to 
the Paumotu Islands; this is called the Micronesian route. The 
other way, the Melanesian route, started from the Fiji Islands, 
belonging to the Australian continental fauna, whence the respective 
animals crossed over by drift to the Tonga and Samoan groups. 
By this way Torresian, as well as antarctic elements, both being 
represented in the Fijis, have contributed to the Polynesian fauna, 
while by the first way only Indo-Malaysian (closely connected with 
the Torresian) elements could immigrate. 
We cannot deny that this theory of the origin of the Pacific faunas 
has many points in favor of it; especially the explanation of the 
connection of the continental faunas of Australia, New Guinea, etc., 
to New Zealand seems very acceptable. On the other hand, Hedley's 
opinion of the oceanic nature of the Polynesian fauna cannot be 
accepted without comment. Indeed, there seems to be a sharp line, 
just where Hedley draws it, between Fiji on one side and the Tonga 
and Samoan groups on the other; but whether the * disharmonic" 
fauna of Polynesia is to be explained by, and is synonymous with, 
“oceanic origin” remains to be demonstrated. The terms “ har- 
monic” and *disharmonic" — although they may be useful some- 
times — are only of relative value; New Zealand, for instance, has 
decidedly a “ disharmonic " fauna, but Hedley himself believes it to 
be of continental origin. 
And, further, the theory of the oceanic origin of the Polynesian 
fauna is opposed to the views of some of the most prominent recent 
writers in Zoédgeography. Hedley refers only to the opinion of G. 
Baur (as expressed in No. 31, 1897, of this journal), and, indeed, in 
one of the instances which he quotes (p. 412) Baur’s argument 
derived from the distribution of Pocillopora and Trapezia is not very 
convincing. But there is another vigorous champion of the conti- 
nental origin of the Polynesian fauna, namely, H. von Ihering, and 
his arguments are certainly worth discussing. Von Ihering traces 
the continental origin of the Polynesian fauna far back into the 
Mesozoic time and thus explains the ** disharmonic " character of-it ; 
