12 THE COMMON RATS 



As the Norway rat did not reach western Europe until 1727- 

 1730 it follows that the European rat of the middle ages, the 

 rat of the legends of the Pied Piper 3 (1284), of the great plagues 

 (before 1700) and of the early anathemas against vermin, was 

 Mus rattus. 



The species first brought to South America on the ships of 

 the very early explorers was Mus rattus (Vega, 1609; de Ovalle, 

 1646). Pennant (1781) gives 1544 as the date of arrival in Peru. 4 

 We have also a notable instance of a plague of these rats in the 

 Bermudas in 1615 (Lefroy, 1882). 



Of the two species in question, Mus rattus is alone recognized 

 by Linnaeus in his Fauna suesica 1746, and in his Systema 

 (1758 and 1766). It does not concern us here to follow the his- 

 tory of Mus rattus in the United States further than to say that 

 this species only (represented by the two forms) was present up 

 to the time of the arrival of the Norway rat in North America 

 toward the end of the eighteenth century, and that Mus rattus 

 rattus the black rat is still found in a number of scattered 

 localities in the northern United States, while in the southern 

 states, Mus rattus alexandrinus is much the more common. It 

 does not appear that either of these forms has ever penetrated 

 far into the interior of the country. 



Turning to the cosmopolitan Mus norvegicus the species at 

 present established in China, Japan, India, western Europe and 

 temperate North America we find that the historical record of 

 its movements, though by no means complete, has the virtue of 

 being recent. 



v. Gesner (Historia animalium, 1551) mentions a Mus aquati- 

 cus which appears to be the form now called Norvegicus, but 

 apparently he himself had never seen it. 



According to Pallas (1831) the Norway rat invaded Europe 

 from the East early in the eighteenth century and was observed 



3 It may be noted in passing that the ancient inscriptions in Hameln relating 

 to the Pied Piper do not mention the rat (Meinardus, 1882). 



4 Pennant (1781) says there were no rats in South America before the time of 

 Blasco Minez. Minez is evidently a misprint for Nunez; Blasco Niinez being 

 the first Viceroy of Peru, from 1544-1546. 



