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. Boiler's Mus novce- 

 zealandice was a specimen — as indeed, he himself seems to think. 



3. 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 

 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 agamst 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 

 type. 



In the next place we must ask, — Is our rat the same as that described by 

 Dr. Buller and called by him Mus novm-zealandia ? 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. hi., p. 3) 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* 



