148 Ipswich Museum. 
deduction as to the terrestrial character of the birds, and the relative 
shortness of the ankle-bone (metatarsus) as compared with that in the 
Ostrich, proved the original surmise as to the more sluggish character 
of the bird to have been correct. 
Successive sets of bones of the great extinct birds were subsequently 
acquired, either by purchase or donation, by Professor Owen, who in 
1846 published his third memoir on the subject, describing the 
structure of the back-bone (vertebree) and the breast-bone (sternum) 
of the Dinornis. The latter he described as one of the most charac- 
teristic bones in the skeleton of a bird; it usually presents a part 
called the “keel,” the depth of which is in the ratio of the size and 
power of the muscles used in flight, the keel being totally wanting in 
birds that are unable to fly. Thus the breast-bone resembles a shield 
in the Ostrich, Emeu, Cassowary, and Apteryx, but each of the 
existing wingless birds has the shield-shaped sternum of a peculiar 
pattern. The sternum of the Dmornis was equally devoid of a keel, 
and in its shape it most resembled the sternum of the Apteryx. From 
the size and strength of a bone of the neck (cervical vertebrze), also 
described and figured in the third memoir, the author had been led to 
certain inferences as to the kind of food on which these gigantic birds 
found subsistence in the small island to which they had been so singu- 
larly restricted; but still the head and beak were wanting, upon which 
any precise idea of the food of the species could be founded. 
In 1847, the researches of Mr. Walter Mantell in New Zealand 
were rewarded by the discovery of the much-wished-for bones of the 
head and beak, and these specimens formed the subject of a memoir, 
published in 1848, in which they were described and figured, and 
referred to four distinct genera of birds. To two of these genera 
belong the largest bones of the wingless birds that have been dis- 
covered in New Zealand. They were called Dinornis and Palapteryx 
respectively. Magnified diagrams of the skull and beak of each were 
exhibited and explained by the Professor ; who concluded by some 
general remarks on the geographical distribution of the known exist- 
ing and extinct birds, the laws or conditions of which were illustrated 
by analogous facts in the distribution of the species of quadrupeds. 
Had all the terrestrial animals, he observed, that now exist, diverged 
from one common centre within the limited period of a few thousand 
years, it might have been expected that the remoteness of their actual 
localities from such ideal centre would bear a certain ratio with their 
respective powers of locomotion. With regard to the class of Birds, 
one might have expected to find that those which were deprived of 
the power of flight, and were adapted to subsist on the vegetation of 
a warm or temperate latitude, would still be met with more or less 
associated together, and least distant from the original centre of 
dispersion, situated in such a latitude. But what is the fact? The 
species of no one order of birds is more widely dispersed over the 
earth than the wingless or struthious kind. Assuming that the 
original centre has been somewhere in the south-western mountain 
range of Asia, there is but one of the species of flightless birds whose 
habitat can be reconciled with the hypothesis. By the neck of land still 
