330 MUSK-RATS. [CHAP. XXXVIII. 



accumulated in one of these hummocks, at least a 

 cart-load, is surprising. We waded through the 

 water to one of them, and found that it was four feet 

 high, and nine feet in diameter. When we pulled it 

 to pieces, the smell of musk was very perceptible. 

 At the depth of about sixteen inches from the top 

 we found a cavity, or chamber, and a small gallery 

 leading from it to another chamber below, from 

 which a second gallery descended, and then went up 

 wards again to a third chamber, from all which there 

 was a perpendicular passage, leading down to below 

 the level of the water, so that the rats can dive, and, 

 without being seen again, enter their apartments, in 

 which they breathe air. 



The unio, or freshwater mussel, is a favourite food 

 of these rats, and they often leave the shells on the 

 banks of the American rivers, with one valve entire 

 and the other broken. In the evening the note of 

 the bull-frog, in these swamps, reminded me much of 

 the twanging of a large Jew s harp. 



From Acquia Creek, I went, by steamer, to Wash 

 ington, and thence by railway through Philadelphia, 

 to the town of Burlington, in New Jersey, beauti 

 fully situated on the banks of the Delaware. Here 

 I paid a short visit to my friend, Mr. William 

 M llvaine, and crossed the Delaware with him to 

 Bristol, to renew my acquaintance with Mr. Vanux- 

 em, a geologist of no ordinary merit. His death, 

 which happened soon afterwards, was a loss to the 

 public as well as to many personal friends. 



In Wilson s &quot; Ornithology&quot; it is stated, that the 

 humming-bird migrates from the South to Pennsyl- 



