SOUTHERN FAUNA, 237 
host of congeners, one and all alien to the population 
predominant in America, and indicating importation 
probably in the Tertiary period ; unless it be assumed, 
with Riitimeyer, “that implacental mammals were 
created out of Australia as well as in it.” 
Among the first to be mentioned are the wingless 
birds, that is, those which are anatomically and syste- 
matically connected, and which we now find scattered 
over continents and some of the larger islands. The 
cassowary of New Holland and America, the extinct 
giant birds of Madagascar and New Zealand, the 
* African ostrich, which has advanced from the south 
northwards, cannot have originated in their present 
isolation. The same considerations are forced upon 
us by the mammals named Bruta by Linnzus, and 
by modern zoologists ‘termed Edentata, by reason of 
their imperfect dentition, among which, accepting the 
latter definition, must be included the Ornithorhyncus, 
or duck-mole of Tasmania. These duck-moles incon- 
testibly occupy the lowest grade among the mammals 
now extant; but the other true Edentata are no less 
alien to the higher orders, and their occurrence in South 
America on the one hand, and in South Africa and 
South Asia on the other, as well as the impossibility 
of tracing them from a common centre in the northern 
hemisphere, points to the vanished land of the south, 
where perhaps the home of the progenitors of the Maki 
of Madagascar may also be looked for. 
“ Or,” says Riitimeyer, “ does the hypothesis of a Polar 
land, once possessing an abundance of animal life, partly 
covered by the ocean and partly by a coat of ice, appear 
an unfounded assumption to us who now witness the 
