Geographical Distribution. 205 
the inhabitants should form as it were, little worlds of 
their own, more or less unlike the inhabitants of any 
other parts of the globe. And next, that some of 
these inhabitants should present us with independent 
information touching archaic forms of life. For it is 
manifestly most improbable that the course of evo- 
lutionary history should have run exactly parallel in 
the case of these isolated oceanic continents and in 
continents elsewhere. Australia and New Zealand, 
therefore, ought to present a very large number, not 
only of peculiar species and genera, but even of 
‘families, and possibly of orders. Now this is just 
what Australia and New Zealand do present. The 
case of the dog being doubtful, there is an absence of 
all mammalian life, except that of one of the oldest 
and least highly developed orders, the Marsupials. 
There even occurs a unique order, still lower in the 
scale of organization—so low, in fact, that it deserves 
to be regarded as but nascent mammalian: I mean, 
of course, the Monotremata. As regards Birds, we 
have the peculiar wingless forms alluded to in a 
_ previous chapter (viz. that on Morphology) ; and, with- 
_ out waiting to go into details, it is notorious that the 
faunas of Australia and New Zealand are not only 
highly peculiar, but alsosuggestively archaic. Therefore, 
in both the respects above mentioned, the anticipations 
of our theory are fully borne out. But as it would 
take too long to consider, even cursorily, the faunas 
and floras of these inimense islands, I here allude to 
them only for the sake of illustration. In order to 
present the argument from geographical distribution 
within reasonable limits, I think it is best to restrict 
our examination to smaller areas ; for these will better 
