Dr. J. E. Gray on the Acclimatization of Animals. 295 
display cannot be surpassed in any country.” Few countries were 
so badly supplied by nature with useful animals and plants as the 
Australian continent ; and while we do not receive in Europe a single 
indigenous product for our tables, either animal or vegetable, from 
Australia, which in this respect has added nothing to the comforts 
of civilized man, no country has been more richly supplied with the 
useful products of other parts of the world; for not only have the 
natural productions of the temperate regions of Europe been largely 
introduced, but even the flowers and fruits of tropical and subtropical 
regions. 
There is no doubt that the introduction into Australia of animals 
long domesticated in Europe is far more easy than that of semi- 
domesticated animals from countries in a ruder state of society. 
Perhaps this may explain why the leading animals and plants to 
which Dr. Bennett refers in this Report, and which, be it observed, 
have all been introduced by individual enterprise, have succeeded so 
much better than the later attempts to introduce such animals as 
the Llama and various ornamental Mammalia and birds. Among 
other attempts referred to are the blackbirds, thrushes, starlings, and 
skylarks of Europe: these latter seem to be established in the Bota- 
nic Garden, but it is doubtful whether such birds can find their ap- 
propriate food except in cultivated gardens or near the towns. 
On the other hand, it is to be observed that the introduction into 
a new country of domestic or semidomestic animals is not always an 
unmixed advantage. Thus, the domestic pig has been completely 
naturalized in New Zealand: there its great multiplication has ren- 
dered it so mischievous a pest to the sheep-farmer, from its follow- 
ing the ewes and eating the newly dropped lambs, that the flock- 
masters have been compelled to employ persons to destroy the pigs, 
paying for their destruction at the rate of so much per tail; many 
thousands are thus destroyed in asingle season. Indeed it has been 
proved by Dr. Hooker’s interesting paper “On the Replacement of 
Species’ that the introduction of a new animal or plant often results 
in its destroying and taking the place of some previous inhabitant, 
_ thus rendering its introduction a matter of doubtful advantage, or 
at all events a question to be approached with considerable caution. 
It is, however, manifest that, on the whole, more useful results are 
to be obtained from the introduction of races already domesticated 
into countries to which they have not reached, than from the attempt 
to acclimatize animals for the most part either unsuited to the climate 
or capable only of an inferior degree of domestication, or inferior in 
quality to those which are already in possession of the ground. 
Under the third head, the cultivation of fish, I have very little to 
observe, although the subject is unquestionably one of great import- 
ance. But as yet we have very little practical information upon the 
question ; and I consider that the advocates of the system are only 
for the present feeling their way, as the experiments have not been 
pursued for a sufficient length of time to produce any positive 
or reliable results. To replenish rivers in which the fish which 
formerly inhabited them have been destroyed, it is necessary closely 
