204 Transactions.— Zoology. 
1. The Mus decumanus—Norwegian rat—which has driven away the 
Kiore Maori into remote districts, if it has not exterminated it altogether. 
2. A species of Mus rattus, of which perhaps Dr. Buller's Mus nove- 
zealandie was a specimen —as indeed, he himself seems to think. 
8. A smaller species—for which Professor Hutton proposes the name 
Mus maorium (Trans., vol. ix., p. 348). 
Now let us first enquire if our rat is the Mus decumanus. I think 
certainly not. I have had a Norwegian rat and two of our present invaders 
stuffed and grouped together for exhibition in our museum. A moment's 
inspection suffices to show what different animals these are. The fur of the 
Norway rat is thinner, shorter, and different in undercolour at all events. 
The eyes, too, are smaller. Our new friend is more like a big field-mouse 
than a Norway rat; and besides being considerably smaller, he is slightly 
i darker in colour and less malodorous. He differs also in his habits, climbs 
trees and flax plants, is phytophagous rather than carnivorous, prefers the field 
to the house, the garden to the sewer ; is less sagacious and crafty in preserv- 
ing himself against his enemies. Some may think him a degenerate form of 
his Norway congener, his degeneracy produced by bush life and scanty fare. 
I do not think so. The argument from difference in size is too important. 
Besides the Mus decumanus, when it takes to the bush, attains a size which 
is greater than that of the animal which haunts the abodes of man. 
Taking to the bush, for a rodent apparently does not by any means 
necessarily imply starvation of individuals and general deterioration of 
In the next place we must ask,—Is our rat the same as that described by 
Dr. Buller and called by him Mus nove-zealandie? Comparing the 
descriptions of the two animals it will be seen that although their charac- 
teristic features agree pretty well in other respects, yet in the matter of size 
one is a comparative pigmy. If Dr. Buller’s rat was the true Kiore Maori, 
and there was only one species of that animal, ours can scarcely be said to 
be the Maori rat. But when the natives told Dr. Buller that the rat from 
Wangaehu was the true Kiore Maori were they right? At the discussion 
which took place on the subject in the Wellington Philosophical Society, 
(Trans., vol. iii, p. 8) the question arose “whether any native now 
living could really identify the native rat." And truly the point is very 
doubtful. I have tried by means of an interpreter to get information on 
the matter from amongst the Maoris who have thronged into Nelson during 
the last week for Land Court business. But their stories and accounts are 
anything but consistent with one another. They do not by any means seem 
to be quite clear as to there having been in olden times only one kind of rat 
in the country, and in all cases their information seems to be traditional, 
