White. — On the Bats of New Zealand. 257 



"I can find no authority as to whether the black rat 

 exterminated the Maori rat. It is generally supposed that 

 the brown rat is responsible (Buckland, p. 63). That seems 

 to have been the impression of the early travellers and 

 missionaries in New Zealand (E. Dieffenbach and Rev. T. 

 Chapman, quoted in Trans. N.Z. Inst., voLiii., p. 1). But it 

 seems probable to me that both brown and black had a hand 

 in it. No doubt both species were brought by ships, and 

 existed, or even exist, in the colony together, as, according 

 to Moseley ('Challenger' Exp.), they do in Malay Islands 

 and elsewhere. 



" I may mention that Darwin found rats at Galapagos and 

 Keeling, which he calls black rats. Although somewhat 

 smaller than the English variety, he does not think it neces- 

 sary to make a new species. 



" Chapman says that in old times there was a second 

 native rat larger than the Norway rat, which was always 

 rare (Trans. N.Z. Inst., vol. hi., p. 1)." 



I take this opportunity to thank those gentlemen who have 

 so kindly assisted me in collecting material for this paper, and 

 will now give an extract from " An Introduction to the Study 

 of Mammals," by Sir W. H. Flower and Richard Lydekker 

 (just come to hand) : — 



" The brown or Norway rat (M. decumanus) is a heavily- 

 built animal, growing to 8in. or 9in. in length, with a bluff, 

 rounded head, small ears, and a comparatively short tail, 

 which is always shorter than the head and body combined, 

 and generally not longer than the body alone. The colour is a 

 uniform greyish-brown above and white below, the ears, feet, 

 and tail being flesh-coloured. Black varieties, which are often 

 mistaken for true black rats, are by no means rare, but the 

 differences in size and proportions form a ready means of dis- 

 tinguishing the two. The brown rat is believed to be a native 

 of Western China, where a race (M. humiliatus) has been dis- 

 covered so like it as to be practically indistinguishable. Both 

 this and the next species agree in their predaceous habits, 

 omnivorous diet, and great fecundity. They bear four or five 

 times in the year from four to ten blind and naked young, 

 which are in their turn able to breed at an age of about six 

 months, the time of gestation being about twenty days. The 

 black rat (Jf. rattus) is a smaller and more lightly- built species, 

 generally not more than 7in. in length, with a slender head, 

 large ears, and thin tail of about Sin. or 9in. in length. The 

 colour is usually a glossy bluish - black, somewhat lighter 

 below ; but in the tropical variety described as M. alexandrinus 

 the general colour is grey or rufous, and the belly white. The 

 disposition of the black rat is rudder than that of M. decumanus, 

 and the white and pied rats kept as pets mostly belong to this 

 17 



