MESSES. A. AND E. NEWTON ON THE OSTEOLOGY OF THE SOLITAIEE. 357 
Islands of New Zealand. This rupture would certainly tend still more to affect the 
existing fauna and flora, and, at the end of another epoch, there can he little doubt but 
the animals and plants of each portion, exposed to different influences, would present 
a decidedly different appearance, and the eastern and western islands (supposing the 
separation to have taken place longitudinally) might each possess its own special form 
of Solitaire, as the islands composing New Zealand have their peculiar species of 
Apteryx. 
But it is only in such case as that which we have imagined that considerable modifi- 
cations would be likely to be effected. It seems, therefore, to us not to be an argu- 
ment against the existence of such a process as that of “ Natural Selection,” but in re- 
ality an argument in its favour to find a small oceanic island tenanted by a single spe- 
cies, restricted in its range, which was subject to very great individual variability. In- 
deed a believer in this theory would, we think, be inclined to predicate that it would 
be under just such very circumstances that the greatest amount of variability would be 
certain to occur. In its original state, attacked by no enemies, its increase would be 
only dependent on the supply of food, which, one year with another, would most likely 
not vary much ; the form would continue without any predisposing cause to change, and 
thus no advantage would be taken of the variability of structure presented by its indi- 
viduals. 
On the other hand, instead of speculating on what might have come to pass, it is perhaps 
more profitable to reflect on what certainly did take place. Of the other terrestrial mem- 
bers of the avifauna of Rodriguez but few now remain. A small Finch ( Foudiafiavicans *) 
belonging to a group almost entirely confined to Madagascar and its satellite-islands, 
but specifically distinct, and a Warbler ( Drymceca rodericana *) belonging to a geuus 
extending to Africa and Australia, though mainly represented in India and the adjacent 
territories, but also specifically distinct, are the only two land-birds of its original fauna 
which, so far as we know, now exist. The Guinea-fowl and the Love-bird have in all 
probability been introduced from Madagascar*; but the blue and green Parrotsf, 
and the slate-coloured Pigeons J, of which Leguat speaks, have vanished with the 
Solitaire. The remains of one of the first, and the description of the last, leave little 
room to doubt but they also were closely allied to the forms found in the other 
Mascarene Islands and Madagascar, and thus it is clear that certainly four out of the five 
or six indigenous species had their natural affines in other species belonging to the 
same zoological province. It seems to us impossible on any other reasonable suppo- 
sition than that of a common ancestry to account for this fact. We are compelled to the 
* Proe. Zool. Soc. 1865, pp. 46-48, pi. i. ; Ibis, 1865, pp. 148-150. 
t Leguat, op. cit. 1st ed. i. pp. 67, 107, and 132 ; Engl, transl. pp. 49, 77, and 95. On the fragment of a 
maxilla of a Parrot sent with the Solitaire’s bones, Professor Alphonse Milne-Edwards has founded bis Psittacus 
rodericanus (Ann. des Sc. Nat. oeser. Zool. viii. pp. 145-156, pis. 7, 8; Comptes Eendus, lxv. (Dec. 30, 1867) 
pp. 1121-1125. 
t Leguat, op. cit. 1st ed. i. p. 104 ; Engl, transl. p. 75. 
