366 ZOOLOGICAL POSITION OF THE ALBINO RAT. 



The species first brought to America on the ships of the very early explorers 

 was Mus rattus alexandrinus . 



Concerning its arrival there is little exact information. The earliest date 

 given is 1548 and later we have one instance of a plague of these rats in the 

 Bermudas in 1615. 



Mus rattus, the black rat, is the only form recognized by Linnaeus in his 

 Fauna Suecica, 1746, and the only form given in his Systema, 1766. It does not 

 concern us here to follow further the history of Mus rattus in the United States. 



Returning to Mus norvegicus — the species at present dominant in China, 

 Japan, seaboard India, western Europe and temperate North America— it may 

 be stated that no significance can be attached to the specific name, norvegicus, 

 given by Erxleben. The historical record of the movements of this species, 

 though by no means accurate, has the virtue of being recent. 



Gesner (Historia animalium, 1620) is said to allude to the form now called 

 norvegicus, but had apparently never seen it himself. 



Authorities agree that the Norway rat invaded Europe from the east early 

 in the eighteenth century, when it was observed in large numbers crossing the 

 Volga in the Russian province of Astrakhan. Pallas ('31) gives 1727 as the 

 year of this migration In view of other dates, this can hardly be the date of the 

 first invasion. The Norway rat reached England— by ships— about 1728-1730, 

 and was soon designated the "Hanover" rat by those who wished to connect 

 the misfortunes of the country with the recently established house of Hanover. 

 There is, however, no reason to suppose that the Norway rat had yet reached 

 Germany, and the name has a political rather than a scientific interest. 



In 1750 the Norway rats are reported to have reached eastern Prussia and 

 in 1753 they were noticed in Paris. Their early distribution to other localities 

 in Europe need not be recounted, but there is evidence that they spread rapidly 

 and soon displaced more or less completely the Mus rattus which had preceded 



them. • v. 



The arrival of the Norway rat on the north Atlantic seaboard of the United 

 States is variously given as 1755 (Zuschlag, p. 26) and 1775 (Lantz, '09). Al- 

 though the exact date is hardly important for our present purpose, yet on the 

 other hand, exact dates are always of value as matters of record, and I wish to 

 call the attention of those who may be interested to the importance of any 

 references which might be obtained from colonial diaries or letters in the last nan 

 of the eighteenth century. Such references would be very welcome. 



This brief account suffices to show that the Norway rat was brought to^tn 

 United States about the middle of the eighteenth century or a little later * we 

 rattus was already in possession, but in the course of the years, how rapi y 

 do not know, the Norway rat became the dominant form, at least in the no 

 latitudes of this country, moving along the trade routes to all points 

 furnish a continuous food supply, and a mqderate temperature. .. 



The Norway rat shares with the black rat the reputation of being a g 



Mus 



