46 MICE. 



surface, as they play over pools and streams. They love to 

 frequent waters, not only for the sake of drinking, but on 

 account of insects, which are found over them in the 

 greatest plenty. As I was going some years ago, pretty 

 late, in a boat from Richmond to Sunbury, on a warm 

 summer's evening, I think I saw myriads of bats between 

 the two places ; the air swarmed with them all along the 

 Thames, so that hundreds were in sight at a time. 



LETTEE XII. 



TO THE SAME. 



November 4, 1767. 



SIR, It gave me no small satisfaction to hear that the 

 falco* turned out an uncommon one. I must confess I 

 should have been better pleased to have heard that I sent 

 you a bird you had never seen before ; but that I find would 

 be a difficult task. 



I have procured some of the mice mentioned in my former 

 letters, a young one, and a female with young, both of 

 which I have preserved in brandy. From the colour, shape, 

 size and manner of nesting, I make no doubt but that the 

 species is nondescript. They are much smaller, and more 

 slender, than the mus domesticus medius of Bay, and have 

 more of the squirrel or dormouse colour. Their belly is 

 white ; a straight line along their sides divides the shades of 

 their back and belly. They never enter into houses ; are 

 carried into ricks and barns with the sheaves ; abound in 

 harvest ; and build their nests amidst the straws of the corn 

 above the ground, and sometimes in thistles. They breed as 

 many as eight in a litter, in a little round nest composed 

 of the blades of grass or wheat.f 



One of these nests I procured this autumn, most artifi- 



* This hawk proved to be the falco peregrinus a variety. 



f We are indebted to Pallas for much information respecting these curious 



little animals, which he calls the mus minutus. He found them in the woods 



in many parts of Russia, and they have since been discovered in Germany. 



The nest is most elaborately constructed of the common reed, formed into a 



