52 
JOURNAL OF THE PLYMOUTH INSTITUTION. 
every part of the coast of both North and South Islands in 
1769-70; indeed the earth retained alike their bones and their 
secret, until it was proclaimed by the voice of science from the 
other end of the earth. This was done by Owen in 1839, from the 
fragment of a bone given him by Mr. Rule for examination, with 
the statement that it was found on the east coast of New Zealand. 
Since this date a very large number of bones have been collected 
from both North and South Islands, and have been submitted to 
the same celebrated anatomist, who has been enabled to determine 
no less than fifteen distinct species, some of them being common 
to the two islands whilst others seem confined to one only. 
After speculations as to the cause of the rapid extinction of the 
Moa, a few of the characters peculiar to the skeleton of Dinornis 
were noticed, as taken from Owen's celebrated papers on the genus, 
showing that the form and structure is so peculiar as to be referable 
to no known family. 
After a brief notice of the other extinct brevipennate birds of 
the Southern Hemisphere, the paper was brought to a conclusion 
with a few remarks on the distribution of these anomalous forms of 
life, the first thing noteworthy being the circumscribed area over 
which they ranged, for an explanation of which the geological 
record is consulted in vain, for as yet an examination of the earth's 
crust has revealed nothing beyond the fact that the entire absence 
of indigenous mammals from their area is one that has always 
prevailed. 
Owen seems to favour the opinion of many scientific speculators 
who think that we have in New Zealand a portion of the earth 
which has been longest upraised from the ocean of any part of its 
surface ; whilst a favourite hypothesis with some is the existence, 
at one time of the earth's history, of a vast southern continent, 
devoid of mammals, and stocked with kindred forms of life to 
those which we have been considering, and which is now altogether 
submerged with the exception of those islands. 
Lastly, the disciples of Darwin and Wallace might see no 
necessity for any of these surmises, but might assume that a 
common progenitor of these brevipennates had at some time existed 
possessed of powers of flight, enabling it to transport itself at will 
over vast spaces; but when, through change in surrounding con- 
ditions, and having no longer any enemy to dread or migration 
to accomplish, those powers of flight became no longer ad van- 
