46 
were minutely detailed, and the different proportions of the toes cha- 
racteristic of different species, especially of the two most gigantic, 
viz. the Dinornis giganteus of the North island, and the Palapte- 
ryx robustus of the turbary deposits of the Middle island. The 
adaptation of the claw-bones for scratching up the soil was obvious 
from their shape and strength. The generic distinction of Palapteryx 
had previously been indicated by a slight depression on the metatar- 
sus, supposed by the author to be for the articulation of a small back- 
toe, as in the Apteryx ; and he had since received a specimen of the 
principal bone of that toe, which was exhibited and described. A 
nearly entire sternum, a portion of a minute humerus, and a cranium 
of one of the smaller species of Dinornis, were also exhibited and 
described. 
This magnificent series of remains of great New Zealand birds had 
been collected chiefly by the late Colonel Wakefield, and had been 
transmitted to the author through the kind interest of J. R. Gowen, 
Esq., a Director of the New Zealand Company. 
March 12, 1850. 
W. Spence, Esq., F.R.S., in the Chair. 
The following papers were read :— 
1. Frrst THouGuts oN A Puysi0LOoGIcAL ARRANGEMENT OF 
Birps. By Epwarp Newman, F.L.S., F.Z.S. etc. 
The systematic arrangement of the Class Aves is more unsettled 
than that of any other portion of the animal kingdom, a circumstance 
that may fairly be attributed to our attaching too high a value to 
characters purely structural or admensural, while we neglect others 
more intimately connected with reproduction ; in a word, to the sub- 
stitution of physical for physiological characters. In mammals, rep- 
tiles and fishes, we have a primary division based entirely on physio- 
logy: thus mammals are placental or marsupial ; reptiles are ovipa- 
rous or spawning ; fishes are viviparous or spawning ; and this primary 
division of these classes is admitted by all physiologists to be strictly 
natural. Notwithstanding, however, the purely physiological charac- 
ter, on which these primary divisions depend, it is found that physi- 
cal characters harmonise with physiological, and that intimate struc- 
ture in each instance bears out physiological difference. It were not 
wise altogether to discard structural differences even in the outset of 
an inquiry into system, but it is necessary to use them rather as cor- 
roborative than as indicative; and above all to draw a distinct and 
permanent line between such as are truly intimate and such as are 
purely adaptive. It has always appeared to me that one of the chief 
advantages of an extensive Vivarium like that possessed by our Society 
is the opportunity it affords for studying animated nature in an ani- 
