120 
president’s address. 
one ought to say scarcely any, and those not very archaic. It has 
been said that the curious Pigeon found in the Samoan Archipelago, 
Didunculus strigirostris, is an archaic form allied to the extinct 
Dodo. In the ‘Zoological Record’ for 1880 the genus Didunculus 
is referred to the Dididae. Beyond a superficial resemblance in the 
shape of the bill, which is absolutely destitute of any taxonomic 
value, I do not know of a scrap of evidence to warrant such an 
extraordinary conclusion. The shape of the bill is largely relied on 
as a generic character, but in most cases it would be difficult to find 
a character of less value. The shape of the bill is correlated with 
the nature of the food. It does not matter whether the change be 
directly produced by the accumulated effects of use or disuse during 
many generations, or indirectly by the constant weeding out of those 
individuals the shape of whose bills are unsuited, or least suited, 
to the available food, the fact remains that a change of locality is 
most likely to produce a change of food, and the change of food to 
produce a change of bill. 
To place the genus Didunculus in the Dididae is tantamount to 
placing the Swallows with the Swifts : to regard it as a sub- genus 
of Carpophaga might possibly be going farther in the opposite 
direction than the facts justif} r . 
There is, however, an archaic species found in New Caledonia, 
which has not only a genus but a family to itself. Dhinochetes 
jubatus belongs to the Schizorhinal Grallas, a remarkably generalised 
sub-order of birds consisting of half a dozen families, the two 
smallest containing only a single species each, and the largest not 
containing a score species. Its nearest relations have probably 
been comparatively recently exterminated in Australia. 
The Avifauna of the Pacific Islands apparently consists of a 
number of waifs and strays from Eastern Asia, New Guinea, and 
Australia. It is, however, more probable that the genera which are 
common to Polynesia, New Guinea, and Australia, are the 
descendants of species which emigrated en masse from North-East 
Asia more or less simultaneously, in much the same way that 
Pallas’s Sand Grouse has twice within this century invaded Europe. 
No one imagines that the various nearly allied species of Mend a 
