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 (vertebrae) 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 Dinornis 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 vertebra?), 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 



