210 Dr. J. Haast on the Extinct 
into so many species is a mistake, and that future researches 
will prove that what appeared to Professor Owen as several 
well-defined species, were, after all, only various stages of age 
and growth of one and the same kind. However, in this re¬ 
spect the collections of the Canterbury Museum bear a strong 
confirmation of the correctness of the great English ana¬ 
tomist's conclusions. We possess, not only young bones of 
each species, from the chick to the full-grown bird, where (to 
take only one bone as guide) the tarsal epiphysis of the me¬ 
tatarsus is not yet quite anchylosed*, but we have of each 
species a series of specimens generally showing two distinct 
sizes, from which we may conclude that they represent the 
male and female bird of each species. In some instances (of 
which I shall speak more fully in the sequel) we possess of 
each species four distinct sizes, which might represent the two 
sexes of two distinct but closely allied species. 
Although Professor Owen thinks that the back toe (hallux) 
was only a small functionless appendage to the foot and that 
thus the existence or non-existence of such bone is of no con¬ 
sequence, and has therefore felt obliged to abandon this ground 
of generic distinction, I am more convinced than ever that it 
is of great importance, and that the principal division of our 
extinct struthious birds has to be based upon this, as I be¬ 
lieve, constant character f. 
* We possess, amongst others, the leg-bones of a specimen of Di- 
nornis maximus which is in size only second to the largest bones we 
have, but in which this immature character in the metatarsus is not yet 
quite effaced. 
t I formerly believed that an impression observed on the back of one 
of the first metatarsals of Dinornis ingens I ever obtained was there for 
the articulation of the back trochlea; but since then several more speci¬ 
mens of that species have passed through my hands which showed that 
impression either only faintly or not at all. Dr. Jaeger, of Vienna, arti¬ 
culated a small back trochlea with the skeleton of Dinornis ingens found 
iu the Moa-cave of Nelson: but there is no evidence that the small bone 
in question belonged to it. In my first paper of measurements, on p. 85 
of the first volume of the ‘ Transactions’ of the New Zealand Institute, I 
already pointed to the distinct rough groove which invariably exists at 
the back of the metatarsus of a number of species, which I have now 
Ventured to unite under the term Palapterygidce. I may add that a num- 
