196 Lloyd's natural history. 



variety. Subsequently it was considered that it might be a 

 hybrid between the present and the preceding species ; but, in 

 the article referred to above, Messrs. Eagle Clarke and Barrett- 

 Hamilton finally came to the conclusion that it must be 

 regarded as a black, or melanistic race of the Brown Rat. 

 This variety has been recorded from several counties in the 

 east of Ireland, mostly from the neighbourhood of the coast. 

 In addition to this form, pied and white varieties are known ; 

 the latter being true albinos, with red eyes. 



Distribution. — Being carried by vessels to all parts of the world, 

 and thus having become a complete cosmopolitan, the Brown 

 Rat was a later immigrant into Britain than its darker relative. 

 As to the exact date of its arrival in our islands, there is still 

 some uncertainty, and it is probable that the question will never 

 be decided with exactness. Waterton, who detested this inter- 

 loper with a hatred only less cordial than that which he bestowed 

 on the Hanoverian dynasty, maintained that the first specimens 

 were brought over from the Continent by a vessel which reached 

 our shores soon after the year 1688, even if they did not arrive 

 in the very ship which carried the first of the line of Hanover, 

 It is, however, probable that this date is considerably too early. 

 From the testimony of Pallas, it may be taken as certain that 

 large troops of the Brown Rat, migrating westwards from 

 Central Asia, succeeded in crossing the Volga in the year 1727, 

 whence they populated the whole of Russia, and subsequently 

 the rest of Continental Europe. They are reported by Erxleben 

 to have reached Paris in 1750, and to have been carried to 

 England twenty years previously to that date. Professor Boyd- 

 Dawkins is, however, of opinion that the Brown Rat had 

 reached this country a httle before 1730, and we may perhaps 

 therefore put the date of its arrival as 1729, or 1728. Be this 

 as it may, no sooner had the intruder obtained a foothold on 

 British soil than it at once commenced an internecine war 



